The aim of physical-modeling synthesis is to produce realistic performance nuance in whole phrases, not just in single notes. Rather than simply playing samples back, a physical-modeling instrument relies on a painstakingly constructed mathematical model of the real instrument. The model typically factors in components such as, in the case of a wind instrument, a mouthpiece and the shape and length of the pipe. It can also respond to changes in parameters such as breath pressure by altering the tone in a way that replicates what happens in the physical instrument. At its best, physical-modeling technology can produce very realistic sounds.
FIG. 1: You choose your basic model and the -parameters it will use in Brass''s main screen. In Live mode, Brass plays -monophonically.
Arturia's Brass software provides physical models of a trumpet, a saxophone, and a trombone (see Fig. 1). The program can run either as a standalone (with ASIO and Core Audio compatibility) or as a VST, DX, RTAS, or AU plug-in. It allows various MIDI messages to be routed to the modeling parameters in useful ways. In addition, a fully editable library of brass-section riffs is included, so you can cue riffs from different MIDI keys and sound like an expert arranger in a number of popular styles.
Installation and Setup
Brass uses a Syncrosoft USB dongle for copy protection, and though the manual doesn't mention the possibility, I had no trouble transferring the Brass license from Arturia's own dongle to my other Syncrosoft dongle, which contains my Steinberg licenses. Because Brass doesn't use samples, the installation is small — only 51 MB including the program and its presets and riffs.
Arturia's minimum system requirement of a 1.5 GHz CPU seems skimpy, at least on the Windows side. Running a 4-note Brass riff in my 3 GHz Pentium 4 machine took as much as 80 percent of my CPU, according to the Windows Task Manager's Performance meter. To keep the sound from BREAKing up due to CPU underruns, I had to increase the ASIO buffer size of my M-Audio FireWire 410 interface to 1,024 samples at 44.1 kHz. A buffer of that size imposes a barely acceptable 23 ms latency on all MIDI soft synths, not just on Brass.
Several factors come into play when discussing how Brass sounds and whether it can produce tracks that are indistinguishable from those recorded by live players. First, crafting tracks with Brass isn't as easy as playing notes on a MIDI keyboard. Initially, you'll need to learn about the ways the various controllers affect the tone, and then shape each phrase, either with a pencil tool in your sequencer or by overdubbing MIDI mod wheel and slider moves. Second, no matter how well you master the technology, to get the best results, you'll need to understand the idioms of playing and arranging for horns. Third, the mix in which you use Brass will affect how realistic it sounds. In a busy, high-energy funk tune, Brass can sound like a real horn section. If it's playing an exposed trumpet solo from the classical repertoire (see Web Clips 1 and 2), however, it might sound a bit stiff.
Brass doesn't sound sampled. The variations from note to note are subtle but audible, even when Brass responds only to different MIDI Note On Velocities. Vibrato added with the mod wheel sounds much more realistic than do the simple pitch changes created in a conventional synthesizer using an LFO. Adding a pitch bend to the trumpet produces the effect of overblowing through the overtone series, which can be effective if deployed as a smear at the right moment in the music.
In general, however, Brass sounds somewhat thin. It lacks the presence or punch of a real horn player or horn section. That fact is due in part to the models' limited dynamic ranges. Applying Aftertouch to the pressure and timbre parameters and then pressing down on the keyboard causes a less ferocious swell than can easily be produced by a real horn player.
A more serious problem is that the trombone model lacks the low end of even a tenor trombone's range, to say nothing of the extended range of a bass trombone or the pedal tones on either instrument. The low end of the Brass trombone's range is only an octave below middle C, whereas a tenor trombone extends down an additional sixth to E2. According to Arturia, its trombone model became unstable between E2 and B2, with some notes not sounding, so those notes were removed from the trombone model. The company hopes to improve the trombone's performance in its next version. In the meantime, there are a few extra notes at the low end of the tenor sax model's range that can come in handy.
Brass can produce up to 4-note polyphony, but only when playing its internal riffs. If you play it note by note using a MIDI controller or a sequencer track, it's monophonic. An ambience-type reverb is included on the Spacialization page, which is where you position your four performers to the left or right and front or rear.
The synthesis parameters available for real-time interaction are attack, pressure, pitch, timbre, noise, vibrato, vibrato frequency, and (on the trumpet and trombone but not the sax) the depth to which a mute is inserted into the bell. The non-real-time parameters include attack type, the material that the instrument is made of, the number of unison players, the amount of Humanization, and the choice of mute or (in the case of the sax) a choice of three mouthpieces. Wood and glass are included among the materials, and those selections can produce entirely unrealistic but expressive timbres.
FIG. 2: Each Brass preset can have a custom mapping of MIDI control inputs to the parameters of the model. Response curves are selected using the icons at the bottom.
The system by which MIDI messages are mapped to real-time parameters is quite flexible (see Fig. 2). You can route nine inputs (Velocity, Aftertouch, Modulation Wheel, Pitch Bend, Breath Controller, and four assignable Control Change messages) to any of the parameters. The depth and curve of the response are programmable, and several sources can drive one parameter — you aren't limited to one-to-one mappings. It is therefore easy to set up expressive effects such as having the mod wheel increase vibrato depth and rate while increasing pressure and opening up the mute.
An adjustment for fine-tuning is inexplicably missing from Brass's voicing parameters. According to Arturia, that was an oversight and will be corrected in the next update. In addition, the instruments in a section lack individual volume control. When a song file is loaded in the sequencer, Brass's sync-to-host setting isn't restored, but that should be an easy bug for Arturia to fix. On several occasions, when I loaded a song that included Brass into Steinberg Cubase SX3, sax and trumpet models failed to load properly, producing nasty crackles and strange pitch artifacts. But selecting a different preset and then going back to the one I wanted solved the problem.
A handy way to interact with Brass is to assign various riffs to different keys on a MIDI keyboard. By default, the bottom two octaves are used for triggering riffs and the upper three octaves for transposing the riff while it plays, but the split point is movable. The transposition takes effect at the beginning of any new note, so the horns can follow along in sections with intricate harmonies.
Brass has its own piano-roll editor for creating and editing riffs that can be of unlimited length (see Fig. 3). The editor includes a strip chart in which you can draw controllers, a loop-playback button so you can listen while you work, and a quantization menu with basic choices. There's no support for groove quantization.
FIG. 3: The piano-roll editor in Brass has a strip chart for controller data, a variety of tools (above the strip chart), and zoom controls (the triangular handles below the piano roll). Notes for the instrument being edited are shown in a darker color.
You can't record in real time into the piano roll, but that's a minor point because you'll probably want to record new horn riffs into your host sequencer. When you do so, you'll need to instantiate the program four times to play a 4-note riff. That isn't a big deal — it's just less convenient than if one instance of Brass were able to receive on four MIDI channels at once.
When quantization is applied in the Brass editor, you can't apply it to some of the notes; it affects all notes in the riff for the currently selected instrument. And though there's an undo/redo command for piano-roll edits, it doesn't work with quantizing. Further, there's no cut/copy/paste utility. There are, however, utilities for managing the saving and loading of both presets and riffs.
In spite of these issues, basic editing works well. You can import Standard MIDI Files, and Pitch Bend, Aftertouch, and Modulation Wheel data will be included. You can even transpose an entire riff to a different key using one command, and Brass will change major thirds into minor thirds if necessary to match the new key.
A separate controller-edit window is provided for drawing envelope contours to be applied to individual notes. For example, you might want a trumpet preset to have a lot of pressure at the beginning of each note and then back off. In general, adjusting parameters and adding envelopes in Brass is a finicky business. A subtle touch is needed to achieve realistic results.
The library of riffs supplied with Brass is categorized by style: blues, disco, funk, hip-hop, jazz, Latino, military, miscellaneous, Motown, pop, R&B, reggae, salsa, soul, and zouk. Most of the styles contain fewer than a dozen riffs, but reggae has 41, pop 37, and funk 42. Most are two measures long. (Check out the demos at www.arturia.com/en/brass/samples.php to hear some of the riffs in action.)
The riffs are quite lively. Little splats (created with vibrato), breath noise, and sloppy section entrances add a lot to the sense of realism. In a few cases, I felt that these artifacts were overdone or just poorly programmed. The riffs are solid stylistically, so though you'll undoubtedly want to customize them for your own tunes, they provide good starting points if you're less than a Tower of Power — class arranger. In two or three of the riffs, I heard little sonic artifacts that I didn't care for, but overall I was impressed with the arranging and the programming.
Strike Up the Band
Brass provides resources for realism and user control that sampled brass libraries, no matter how good, simply can't match. The program is sure to be embraced by jingle producers who need quick access to high-energy pop arrangements, film-score composers who need to rough out convincing demos, and home-studio owners who want to spice up a funk or Latin track but aren't set up to record a real horn section.
Brass 1.0 suffers from some shortcomings, notably the missing low end of the trombone range and the lack of cut/copy/paste in the piano-roll riff editor. And though you can slam a finger down on a keyboard and hear a sparkling brass-section riff, getting the most out of Brass will require time and patience. Arturia has done a lot to make Brass easy to use, but as with any complex piece of software, those who are in search of instant gratification will miss out on much of the program's power.
Jim Aikin writes regularly for EM, Mix, and other music technology publications.
PROS: Excellent physical models. One-finger riff triggering ideal for live use. Good starter library of stylish riffs.
CONS: Very CPU-intensive. Lacks low end of trombone range. Piano-roll editor needs more utilities.
GUIDE TO EM METERS
5 = Amazing; as good as it gets with current technology
4 = Clearly above average; very desirable
3 = Good; meets expectations
2 = Somewhat disappointing but usable
1 = Unacceptably flawed
On a scale of 1 to 5
EASE OF USE...3
QUALITY OF SOUNDS...4