FIG. C: The MainStage interface is centered around the user-designed control panel for the selected instrument. The Patch List at the left shows the Concert in file browser format. Select an element to see its channel strips (right) and attributes (bottom).
MainStage is a virtual instrument and effects plug-in host designed, as the name suggests, for live performance. The upgrade to Version 2 brings several very useful enhancements. You can load it up with backing tracks (stems or stereo mixes), record and arrange loops in real time, and record total performances in a variety of formats, including Core Audio Format (CAF) for very long sets. You can map onscreen controls to multiple plug-in parameters, as well as create control groups for fast layout design.
MainStage 2 supports ReWire, but it functions only as a host for other ReWire clients. That lets you use the instruments and playback facilities of popular ReWire clients like Propellerhead Reason and Ableton Live in your MainStage performances. Unfortunately, you cannot use ReWire to gain access to MainStage instruments and effects in other ReWire-host programs. You get around that, albeit less conveniently, by using an IAC MIDI bus and an audio routing utility like Soundflower, which is a free download from Cycling ''74.
FIG. D: The Playback plug-in displays an audio file as a tape strip with transport controls and read-outs along the bottom.
MainStage files are called Concerts and have three levels: Concert, Set and Patch (see Fig. C). You can insert mixer channel strips for instruments and effects at any level. Typically, you''ll put instruments at the Patch level, but where you insert aux effects will depend on how broadly you want them to apply. Creating Concerts and custom control panels can take awhile, but MainStage comes with lots of templates, as well as complete setups.
Backing tracks are handled in MainStage 2 by the Playback instrument plug-in, which is exclusive to MainStage and comes in mono and stereo versions (see Fig. D). You can use one Playback plug-in to play a full mix or several of them to manage and play stems from a mix. Grouping channel strips holding Playback plug-ins lets you control their playback parameters (start and stop, for example) simultaneously, and starting one group stops all other groups, so you can use groups to manage song sections. Adding audio files for playback is as simple as dragging and dropping them in the channel strip area of the GUI; each file creates a new channel strip holding a Playback plug-in.
For audio files with tempo information (Apple Loops and bounced Logic songs, for example), you can sync Playback to the MainStage tempo, in which case the Logic Flex modes—Slicer, Rhythmic, Speed and Polyphonic—are supported. If the files contain markers, you can move among them using MIDI commands or onscreen buttons.
Recording loops with the Loopback module is extremely simple. Loopback is an effects plug-in, and if you insert it in an instrument''s channel strip, it will record just that instrument. To use it with several instruments, insert it as a send effect and use the instruments'' send levels to control their relative record levels.
Loopback will guess the loop length from your first recording, or you can specify a length in advance. You can sync it to the MainStage tempo or have it guess both tempo and loop length. Once you''ve recorded the first pass, tempo and length are locked, but you can set recording to start at the next beat, bar or beginning of the loop. In a nice touch, you can set Loopback to start playback relative to the MainStage song position. That''s useful when you''re using several Loopback instances and want to toggle them in and out while keeping them in sync.