
Ultrabeat overview in MainStage
Ultrabeat is a synthesizer that is designed to create percussive sounds and polyphonic rhythms. It also incorporates a powerful step sequencer which you can use to create polyphonic rhythmic sequences and patterns. See Ultrabeat step sequencer overview.
If you’re new to using plug-ins in MainStage, see Add and remove plug-ins in MainStage and Use multi-output instruments in MainStage.
Most software synthesizers offer one synthesizer per plug-in instance. Ultrabeat, however, places 25 independent synthesizers at your disposal. These synthesizers—known as drum voices in Ultrabeat—are optimized for the generation of drum and percussion sounds.
You can compare Ultrabeat with a drum machine that features 24 drum pads, plus a built-in multioctave keyboard that can be used for polyphonic accompaniments, or bass or melody lines. See Play and select Ultrabeat sounds.
The distribution of drum voices across the MIDI keyboard is as follows: a single drum voice is assigned to each of the first 24 MIDI keys (spanning MIDI notes C1 to B2). The 25th drum voice is assigned to the keys from the 25th MIDI key (C3) and above, enabling you to play this sound chromatically.

The 24-drum pad assignment is compatible with the widely adopted GM (General MIDI) MIDI Drum note mapping standard. If your MIDI keyboard is limited to two octaves or does not support transposition, use the Transpose options of MainStage to shift incoming MIDI notes up or down one or more octaves.
Note: For clarity, and to maintain the drum machine analogy, this guide refers to the independent synthesizers as drum sounds. A combination of drum sounds forms a drum kit.