Set the ES2 keyboard mode in MainStage
A polyphonic instrument, such as an organ or a piano, allows several notes to be played simultaneously. Many older analog synthesizers are monophonic, which means that only one note can be played at a time, much like a brass or reed instrument. This shouldn’t be viewed as a disadvantage; instead, it allows playing styles that are not possible with polyphonic instruments.
Change the keyboard mode
In MainStage, click the Poly, Mono, or Legato button.
In Mono mode, staccato playing retriggers the envelope generators every time a new note is played. If you play in a legato style (play a new key while holding another), the envelope generators are triggered only for the first note you play legato, then they continue their curve until you release the last legato played key.
Legato mode is also monophonic, but with one difference: the envelope generators are retriggered only if you play staccato—releasing each key before playing a new key. If you play in a legato style, envelopes are not retriggered.
Note: On several monophonic synthesizers, the behavior in Legato mode is referred to as single trigger, while Mono mode is referred to as multi trigger.