Virtual Bandmates

Modern MIDI sequencers are unquestionably powerful tools for composing. But when inspiration strikes, it can take a lot of time and effort to develop

Modern MIDI sequencers are unquestionably powerful tools for composing. But when inspiration strikes, it can take a lot of time and effort to develop ideas using a sequencer. By the time you finish your drum parts and lay down bass lines, pads, and arpeggios, you easily can find yourself astray from your original creative impulse. Sometimes it's easier to let the computer make some musical choices for you.

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The same idea holds true if you simply want to create some music for practicing. You might find it easy to sequence a piano-and-bass rendition of “Giant Steps” that cycles through all 12 keys, but programming a lively drum part for the tune may not be so easy if you aren't a drummer.

Moreover, the type of controller you play may determine how convincing your parts turn out; chord voicings played on a keyboard are often quite different from those played on a guitar. Keyboardists can try this little experiment: Play a simple G-major chord, “strumming” from low note to high and then high note to low. Now, try playing alternating up and down strums in eighth notes at 100 bpm. It's not that easy, is it? Conversely, guitarists will find playing some piano-chord voicings to be an exercise in futility or an invitation to carpal tunnel syndrome.

The world of MIDI composition would be a mighty dull place if it didn't help musicians travel beyond the boundaries of their musical skills. Fortunately, a handful of clever companies with some interesting ideas about computer-music composition have introduced auto-accompaniment programs. Experienced players may scoff at these tools, but auto-accompaniment programs can enable anyone to create some very stylistically convincing music in a ridiculously short time.

The term auto-accompaniment is really an oversimplification for these programs. You certainly can use the software to generate backing tracks, but you can also try out new arrangements or use portions of the files to generate individual instrument parts for use in a more full-featured sequencing program. You may want to use them to print out quick charts for band rehearsals or rapidly produce a sketch of your ideas while the creative spark is burning. One program will even randomly generate entire songs — complete with melodies, solos, and titles — with a minimum of user input.

I analyzed three of the best-known auto-accompaniment programs: PG Music's Band-in-a-Box Pro (Mac/Win), SoundTrek's Jammer Professional (Win), and MiBAC's Jazz (Mac/Win). Jammer SongMaker is a pared-down version of Jammer Professional with fewer style-editing features and no tempo map. SoundTrek also offers Jammer Live, which interacts with live input but does not generate music on its own. In addition to Band-in-a-Box Pro, PG Music offers Band-in-a-Box MegaPAK, which shares the same program and feature set but includes several more musical styles. Owners of the Pro version, however, can purchase additional styles at any time.

The programs share a few traits; for example, all three rely on a chord-chart metaphor for entering music. It's relatively easy to just jump in and create music with any of the programs, but from there differences abound. The three programs examined here offer widely divergent stylistic and compositional tools; keep in mind that a feature that one musician might consider an asset may be unnecessary or even a hindrance to another.

Each program has inherent strengths and weaknesses from the standpoints of musical authenticity, orchestrational offerings, and even compositional styles. Given the space allotted here, it's difficult to cover every feature of three fairly deep programs; nevertheless, a broad overview such as this may point you toward the program that will best meet your needs.


All of the programs are initially set up for General MIDI (GM) instruments. However, you can set patch maps for just about any synthesizer using Bank Select and Program Change messages. Jazz is the exception — the current version supports only Program Change; a forthcoming update will offer access to FreeMIDI, Open Music System (OMS), and QuickTime Musical Instruments. That will allow you to access any instrument in your MIDI system through multiple MIDI ports. For now the program supports only single-channel MIDI interfaces. Of course, any multiple-port interface that can route inputs to a single port will also work. Band-in-a-Box and Jammer Professional contain patch settings for a variety of popular synthesizers; therefore, if you don't have a GM-compatible synth, you can probably find an appropriate patch for the task.

Non-GM synths may have different transposition settings, so all of the programs allow you to transpose the MIDI output to a suitable range for your device. In addition, all of the programs let you assign alternate notes for drum kits if your sounds don't correspond to a GM or XG drum map. Jazz could stand some updating in that area. You can transpose piano and bass parts one octave above or below the GM standard pitch. In most cases, that range should suffice, but I have seen instruments programmed at higher and lower octaves on occasion. The work-around is to transpose the patch in question to the desired range. Furthermore, Jazz only provides notes for a standard drum kit with no Latin-percussion parts. The manual suggests remapping the standard-drum-kit notes to trigger Latin percussion sounds. However, when I tried that, the resulting performance sounded neither authentic nor musical; after all, drum kits and hand percussion usually do not play redundant parts. It is also too bad that a standard-drum-kit map can't coexist with percussion elements.


Once you've set up your instruments for playback, you're ready to make music. Band-in-a-Box is probably the easiest to jump-start. When you first load the program, it's happy to vamp endlessly on a generic swing groove in the key of C if you let it. Naturally, that can get monotonous, so you'll want to enter chords, set a key signature, and pick a musical style. Band-in-a-Box is pretty flexible about which of those elements you can start with. Unlike the other two programs, you don't have to immediately concern yourself with song form; Jazz and Jammer Professional require you to determine the number of measures in advance. However, Jammer Professional has a sizable list of template files for different types of music to get you started, and you can create your own templates. Jazz doesn't provide any templates, so it's a good idea to invest a bit of time in creating song-form templates. Devise the number of bars you need, type any chord into the measures, and save the file; the program is flexible enough to let you make alterations and conceive details later. All three programs let you enter chords with your computer keyboard; you navigate though the measures with either the left and right arrows or the Tab and Shift keys. Jazz provides a Chord Help window in which you can audition the available chords, select a root and chord quality, and paste a chord into the selected measure. Jammer Professional and Band-in-a-Box let you enter chords with a MIDI controller.


To lay out the basic song structure with Jazz, you simply click on the Form tool in the right-hand column. The dialog box opens and lets you set up intro, chorus, and coda lengths (see Fig. 1). Alternatively, you can choose not to create an intro or coda. You can then select a key signature in the right-hand section of the dialog box, which shows the key and accidentals as you scroll through your choices. Finally, you can choose to loop the song.

Despite its relative simplicity, I found Jazz to be a bit less graceful to get started with than the other two programs. The program is far more literal about the way you assemble your song. In Jammer Professional and Band-in-a-Box, when you leave a measure blank, the previous chord becomes the reference for the blank bar. Jazz's insistence on creating a chord entry for every measure can be fatiguing, especially if you are creating a long song form with lots of measures that hang on a single chord.

Furthermore, if you make a typo while entering chords, such as entering a flat with b instead of Option + B (the program's keystroke for a flat symbol), Jazz doesn't reject the typo until you have completely written and compiled the entire song. On the other hand, if you accidentally type in an R chord, Jammer Professional and Band-in-a-Box will steadfastly refuse to enter it. Jazz will highlight your errors, so you can make corrections, but I would prefer to fix them immediately rather than wait until I've completed the song form. Cleaning up errors at that point can be especially tedious if you have copied and pasted measures with invalid chord entries.

Band-in-a-Box has a significantly more complex user interface than the other programs; in fact, the screen is populated by enough buttons, menus, and icons to confound you at first glance. Nonetheless, creating your song form couldn't be easier. A Title Bar shows the song name, a musical style, a key signature, a tempo, and the range of measures that define a chorus length (see Fig. 2). Clicking on the numbers enclosed in parentheses lets you set the starting measure of your chorus. Measures preceding the start time play only once, automatically defining an intro section, and you can set a tag or coda or let the program automatically generate a two-bar ending. You can assign Part Markers for any group of measures to either an “a” or “b” substyle. The substyles produce different performance variations. For example, an “a” substyle might contain busy piano or guitar comping, whereas “b” might offer a sparser piano with a walking bass. Each substyle contains a number of possible performance variations picked at random to give a more interactive feel to the playback. The program offers two ways to enter chords: you can use the QWERTY keyboard to type them in, or you can play them in one at a time from your MIDI controller. Band-in-a-Box lets you insert four chords per measure (three in waltz styles).


Jammer Professional employs a more linear, modular system for song form (see Fig. 3). With Jazz and Band-in-a-Box, the basic modus operandi is to create an intro, a chorus with a number of repetitions, and a coda — the program creates automatic variations for you. With Jammer Professional, however, individual elements of songs reside in a variety of files containing Intros, Grooves, Breaks, Drum Fills, and Endings. You assign the sections to measures as song structure requires.

If you are content with the choices offered by the templates, load a template and type in your own chords. The strength of this program is that you can customize every (or any) measure of music that Jammer Professional generates, and virtually any individual instrumental performance in the arrangement can be changed at any time. You might be tempted to pigeonhole Jammer Professional as a sequencer with a bunch of prefabricated components, but in fact, the program randomly generates different performances for each section of the song. With a click on the Compose button, you can create a new rendition of the entire song, selected measures, a single instrument, or just the snare part of the drum performance, for example.


Jammer Professional's greatest strength, however, can also be one of its greatest weaknesses. Both Jazz and Band-in-a-Box make it quick and easy to create a song form with a modicum of variation. Jammer Professional will not change or vary styles until you provide a new pattern. Nonetheless, Jammer Professional's modular measure-by-measure, instrument-by-instrument approach is seductive, which is a good thing if you want to experiment with your song. Yet that can be distracting for those who think that just one more drum tweak will provide that truly inspirational practice track.

Both Band-in-a-Box and Jazz offer tools to provide more fine-tuning and customizing, though not at the microlevel that Jammer Professional provides. For instance, Band-in-a-Box lets you create a number of hits, shots, and rests of different durations. You can also formulate rhythmic anticipations at any point in a song with as great as 16th-note precision. Band-in-a-Box and Jazz allow you to write bass pedals with a variety of rhythmic figures. Both programs let you instruct any instrument to lay out for as long as you need.


Stylistically, Jazz is perhaps the most straightforward of the three. The program offers a three-instrument ensemble consisting of piano, bass, and drums. Jazz focuses on four styles: Jazz 4/4, Latin, Slow 4, and Jazz 3/4. Each of the four styles has three substyles: Ballad, Normal, and Up Tempo.

The substyles offer very different feels. For example, the Latin Ballad style has a bit of a shuffle and is reminiscent of late-'60s to early-'70s funk, whereas Latin Normal conjures the feel of Horace Silver's “Song for My Father.” By and large, the comping is excellent with some nicely loose-limbed drum parts. The drums offer the most rhythmic variety in the program with somewhat less rhythmic variation in the piano and bass. I found myself wishing that the instruments would change roles, perhaps with more active bass or piano lines, leaving the drums to hold the rhythmic fort.

You can change styles and substyles at any measure for as long as you like; for example, you can switch from a Jazz 4/4 with an Up Tempo substyle to a Latin Ballad. You can replace the style at the same place for every chorus or at a specific chorus, and you can alter styles for every instrument or for individual instruments. I was able to transform a tune with a Latin groove to one with a swing feel, with the drums shifting to swing a measure early — the way a real drummer would cue the rest of the band. The ability to mix and match styles so flexibly, coupled with the variations included, gives you a hefty measure of musical expressiveness.

Jazz provides additional facilities for tweaking the performance. You can scale Velocity at any measure for all instruments or for individual instruments and make it happen for selected measures or every repetition of those measures. The program lets you transpose measures or “humanize” the performance in a similar fashion.


If you want to create that rendition of “Giant Steps” in all 12 keys, think again. Except in one substyle, Up Tempo, Jazz supports only two chords per measure — a tremendous drawback for a program targeted at jazz pedagogy. Unfortunately, unlike the other substyles, the four-chord substyle provides little in the way of stylistic variation; in fact, the bass line and piano continuously play on every quarter note, which creates an unjazzlike feel.

Surprisingly, Jazz has a limited palette of chord options; for instance, you cannot directly enter slash chords (chord symbols indicating a nonroot tone in the bass). Those chord types have been common in jazz and gospel music for some time. One work-around is to type in the upper part of the chord and then create a bass pedal for the selected measures. However, creating pedal tones constrains the part to the rhythmic patterns offered in the menu and can break up the groove. Additionally, you can't mix 4/4 measures with 3/4 measures or vice versa, and odd meters other than 3/4 are not supported at all.


Jammer Professional caters to a wider variety of tastes, offering rock, pop, jazz, country, and even bluegrass styles. The program supports various time signatures in all genres (as unlikely as a bluegrass tune in 11/8 might seem). Overall, the styles are effective at creating well-played, tight-sounding music, but the program occasionally comes up short in authentic stylistic detail. For example, bluegrass sounds more like a rock musician's concept of bluegrass; the banjo rolls sound more akin to a programmed arpeggiator than to a banjo, lacking any of the rhythmic nuance or drive of the real instrument. I'm no bluegrass purist, but the drumming sounds too heavy-handed, and as any traditionalist will tell you, drums are verboten to begin with. Similarly, the scarcity of jazz distinctions other than swing and a few smooth-jazz flavors may not be your cup of tea.

Still, Jammer Professional has tricks up its sleeve that the other programs don't. The ability to define the song stylistically measure by measure and instrument by instrument is a musical polyglot's delight. You can load new funk variations into a funk tune: try eight bars of funk, eight bars of bluegrass with or without funk drumming, and then segue into a reggae groove with jazzy swinglike horn blasts. Furthermore, every style is replete with customized parts, including synchronized bass and guitar unison parts, vivid ensemble runs, drum fills, and keyboard lines.

Clicking on the Compose button can seed tons of variations on these lines, and stringing together a few measures of the fills can impart an almost Frank Zappa-like, through-composed feel to the music (see Fig. 4). You can lock any of the tracks to prevent an instrument from being edited or recomposed. Instrumental tracks are not limited to preset groups of instruments, and you can build tracks by adding Musicians. A Musician is a track that plays back an instrumental part; you assign styles for the instrument to play. Jammer Professional can also change meter at any measure. The program handles this task remarkably well: funk grooves, for example, with time signatures of 7/8 or 9/8 are not a problem.


Band-in-a-Box has a somewhat awkward way of handling time signatures other than two or four. You can select any range of measures and use the Set Time Signature of Scrap command. Then, choose a number of beats per measure. The change is not always handled smoothly; for example, changing a group of measures from 4/4 to 3/4 simply lops off the end of a measure, resulting in instrumental parts that sound unnaturally curtailed and drum fills that are displaced to new measures. Just the same, altering the time signature provided a few pleasant surprises. Clearly, some styles are better than others at creating odd time signatures; for instance, it is better to create a 5/4 song using a Jazz Waltz with alternating measures of three and two than to use a 4/4 jazz style and add a beat for each measure.

Band-in-a-Box can also change styles at any measure, but it is an all-or-nothing proposition. You can't insert a keyboard part from one style and a drummer from another, for example — you get whichever variations and instruments are contained in a given style. Of course, you can create a new style that contains all of the elements you want, but that's not as quick or as intuitive a process as the method provided by Jammer Professional.

The program offers an almost encyclopedic collection of musical categories, ranging from barbershop quartet to rap and zydeco, with nearly all points in between. Of the three programs, Band-in-a-Box is the easiest for trying out your song in a completely new genre. If you're not happy with your song rendered as a bebop tune, you can select any of the more than 700 styles (including polkas, if your taste allows), and the program will generate your tune in seconds, complete with all of the stylistically correct trimmings.

Many of the Individual styles aim at replicating a specific artist's approach; for example, PopRiff does a creditable job of emulating the feel of “Every Breath You Take” with its arpeggiated guitar parts and simple, pumping bass line. The Meth8081 jazz variation is a remarkable piece of work with wonderfully propulsive drums, strummed acoustic rhythm guitar, and locked-in bass. PG Music can't spell out the inspiration for the style, but it obviously draws from the rhythm section of Pat Metheny, Charlie Haden, and Jack DeJohnette. The program offers a multitude of jazz forms, many with piano comping in the style of well-known artists, including Bill Evans and Herbie Hancock. In all fairness, I'm not an expert on the stylistic nuances of those players, but the performances satisfy my overall impression of their differences.

The original bluegrass styles that the program incorporates are less than authentic. If you want to create bluegrass with more detail and considerably more ethnic flavor and feel, you should check out PG Music's Unplugged collection. Nonetheless, a few problems do crop up in those styles, too. Because the program randomly picks patterns to play back, patterns that play open chords may get selected and transposed with the chord changes. Banjo parts often rely on a droning fifth string, and the drones also get transposed. On the other hand, the rhythmic feel is accurate, and it conveys the realistic, unquantized push and pull of the real thing. Also, be sure to check out Rebecca Mauleon-Santana's authentic Latin grooves, which include Afro-Cuban, Brazilian, and other regional subsets of the genre.


Despite the number of available musical choices, you still may find the need for something other than the programs' preset offerings. With Jammer Professional, you can edit the preset styles to a very high degree for rhythmic feel, tweak note choices and change Velocity nuances, and save the results as a new type. Although you can't create a completely new category from the ground up, the program makes it possible to create some radical hybrids. Jazz, however, has no options for building new styles; what you're given is what you get.

Of the three programs, only Band-in-a-Box allows you to create completely new varieties from scratch. The program lets you play or step-record individual parts for the “a” and “b” substyles. Each substyle contains as many as 30 cells for each instrument. Every cell can be a unique performance, offering plenty of variation on playback. You can also weight the probability that any passage for a given instrument will be selected.


The most recent version of the program provides some exciting Stylemaker shortcuts, including the ability to import any portion of a previously recorded Standard MIDI File (SMF) for use as a style pattern. You can do the same for the drum and percussion parts, too. That gives you the opportunity to invent, clean up, and fine-tune styles if you own a more full-featured sequencer. You can create authentic, properly voiced guitar strums or fingerpicking patterns simply by entering rhythmic single-note macros.

The most exciting new feature is the option to extract and add instrumental parts from any style for use in a completely different style and then save the composite as a new style. In a matter of minutes, I was able to enhance a Guaracha style with a James Taylor-like fingerstyle guitar part. That capability can offer endless possibilities for creating hybrid styles.


After you have created your styles, generated a song, and tweaked it to perfection, you will naturally want to play along; all three programs provide the space for you to do so. However, in its current version, Jazz requires Apple's MIDI Manager and the Patch Bay application to play along with a MIDI controller. On its own, the program doesn't provide a MIDI Thru channel option — that's a serious limitation if your only sound source is a single MIDI keyboard. If you don't want to use MIDI Manager, plan to use a separate keyboard with Local Control set to on or play an acoustic instrument.

The other two programs make it easy to play along, and you can record your jams for posterity. If you'd like to clean up after your recording, Band-in-a-Box provides an event list and a notation window, and Jammer Professional offers an event-list and a piano-roll editor. You can edit any of the tracks in Jammer Professional and save a highly customized version of your song. Band-in-a-Box lets you do the same, but you need to save your tweaks immediately as an SMF before clicking on Play again, because the song will regenerate the performance. Jammer Professional also lets you enter a tempo map, so your song can speed up or slow down as needed. Band-in-a-Box allows one tempo change per measure only; that is too coarse a resolution for accelerandos or ritardandos, but enough for minute variations from bar to bar.


The features that I have detailed so far barely scratch the surface of what these programs offer. For example, all three can create and print chord charts; Band-in-a-Box lets you print your work as a chord chart or in standard notation.

Band-in-a-Box also lets you print any track in tablature. Nonguitar parts are intelligently mapped to proper fingerings, so guitarists can try their hands at playing sax solos. With version 10, you can quickly convert single-note melodies into accurate chord-melody solos in the styles of esteemed jazz guitarists. If that's not enough, you get an editor to create your own favorites.


You can create powerful, expressive music in Jammer Professional just by applying overall Band Styles and clicking on the main Compose button, but you'd be missing a much deeper level of musicianship inherent in the program's modular design. The Compose command is an aggregate of individual Composer types: Rhythm, Melody, Harmony, Percussion, Composers for kick or snare drum, and more. In keeping with the modular concept, these types call up individual Composer styles that you can edit and save. For instance, you can edit a Bass Composer style by providing note, rhythm, and Velocity choices.

Among the three programs, Jammer Professional stands alone with its robust support for MIDI Control Change (CC) messages. Band-in-a-Box lets you set MIDI Pan Position, Main Volume, and Chorus and Reverb levels, but those are static adjustments. Jammer Professional allows you to record and edit any MIDI CC; it can even generate a stream of CCs on its own. That's especially useful for Techno and other contemporary styles that rely heavily on timbral motion.

Since version 8, Band-in-a-Box has offered an extremely powerful Melodist feature that goes far beyond generating a simple melody. You can let the program generate an entire song: melody, chords, and all. If you'd like, the computer can make all of the choices for you, or you can provide your own input at any level of depth that you choose. For example, you can select an overall style, increase the incidence of atypical chord progressions, or create a more legato melody track. Besides offering a great creative kick-start for ideas, the Melodist is an effective practice tool, because you can't be sure what the program will throw at you.

The program's Soloist feature can generate authentic-sounding solos in a wide variety of styles from bluegrass to bop, but some of the rock soloists were too manic. Fortunately, you have controls to reduce the busyness of the solo. (How many times have you wanted that control for your nonvirtual bandmates?)


Band-in-a-Box records a single 16-bit, 44.1 kHz mono audio track and includes a few digital signal processing plug-ins such as reverb and compression. The program also supports DirectX, opening up the process to a wide variety of third-party plug-ins. You can render complete song performances as stereo 16-bit, 44.1 kHz WAV files and burn them to a CD — all without leaving the program.

The wealth of amenities that Band-in-a-Box offers is staggering, and the company aggressively adds updates and new styles. However, the program is not without problems. The user interface could stand some pruning: many buttons occupying precious onscreen space are redundant menu commands. Furthermore, the Mac version's interface and key commands don't always adhere to Mac conventions. For instance, pressing Command + A should select all measures for editing; instead, the command initiates song playback.

More significant, I'm annoyed and disappointed by the feature lag between Windows and Mac versions. At present Band-in-a-Box for Macintosh is only at version 8, whereas Windows users are three upgrades ahead (version 11 for Windows is available as of press time). The new, easier style-creation features and enhanced guitar-oriented MIDI tools are missing on the Mac, and that's a severe letdown.

I'm no less disappointed that Jammer Professional has no Mac version whatsoever. The program provides a unique cross-pollination of traditional linear sequencing and algorithmic composition. The ability to easily edit the elements that generate the music at the level of the individual instrument is intriguing and offers enormous appeal to any musician with a healthy eclectic streak.

Overall, Jazz is in need of a major update. The provided styles reflect little of the change that music has undergone orchestrationally, rhythmically, and harmonically during the past three decades. Multiple-port MIDI interfaces have been around for some time, and the program should be able to take advantage of that capability. Jazz's inability to allow a play-along MIDI channel without using the antiquated Apple MIDI Manager is a serious inconvenience. The addition of a track for recording with your controller is a must-have if you want to save your performance for later evaluation. On the positive side, Jazz is the only program that can run on a 68000 Macintosh; considering the impoverished state of so many music-education labs today, Jazz may be an important option.

Caveats aside, any one of these programs can provide hours of fun wood-shedding with your instrument. Also, they can be tremendous creative tools with the ability to quickly create anything from a sketch to a full-fledged arrangement of your musical ideas. Musical growth depends on practice and creativity, and auto-accompaniment programs can be great companions for both activities.

In a former life, assistant editorMarty Cutlercreated a bunch of Soloists and the Unplugged styles for PG Music's Band-in-a-Box.




Editable Styles

Record Live Performance

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1.61 (Mac)





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PG Music
Band-in-a-Box Pro
10 (Win)





PG Music
Band-in-a-Box Pro
8.0 (Mac)






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