polyphony

Polyphony voice limit.

This can be applied to all regions under a header such as ‹global› or ‹group› or to regions which have the same group opcode value set. The below examples all use the group opcode, not the group header, but that is not the only way to use the polyphony opcode.

In addition to positive integer values, polyphony can also be set to one of three special text values. With all of these, the polyphony limit is set to 1, and the following behavior is also triggered:

• legato_high: the highest note played sounds and lower notes are muted.
• legato_last: the most recent note played sounds (typical legato behavior).
• legato_low: the lowest note played sounds.

Examples #

polyphony=12
polyphony=5
polyphony=legato_low

An example limiting a crash cymbal to four polyphony voices.

group=1
polyphony=4
<region> key=49 sample=crash.wav

Here is a ride limited to a total of seven voices, with both bow and bell articulations sharing the same polyphony group and the same seven-voice limit.

group=2
polyphony=7
<region> key=51 sample=ride_bow.wav
<region> key=53 sample=ride_bell.wav

This opcode is useful for controlling sound buildup, limiting resource use, and for emulating the behavior of vintage keyboards with limited polyphony. It’s also possible to use note_polyphony instead when all the sounds we want to mute each other are mapped to the same pitch, or use both in combination. An alternative for controlling sound buildup is using ampeg_release with off_mode set to normal.

It’s also possible to have a group with limited polyphony which can be muted by another group, such as a cymbal with edge chokes.

<group>
group=2
off_by=3
polyphony=7
<region> key=51 sample=ride_bow.wav
<region> key=53 sample=ride_bell.wav

<group>
group=3
<region> key=54 sample=ride.choke.wav

An alternative is note_polyphony. The difference between applying polyphony across one note and using note_polyphony is that note_polyphony also uses note_selfmask which opens up some additional options. With the default setting, lower-velocity notes do not mute higher-velocity ones. This is useful for long-ringing instruments such as piano with the sustain pedal pressed down or hammered dulcimer. It can also be useful for cymbals, although especially with hi-hats, those will often use different notes for different articulations, and note_polyphony would be limited to working within an articulation.

Category: Instrument Settings, Voice Lifecycle