Exclusive group number for this region.

ARIA adds also the polyphony_group alias to reduce the confusion between the group opcode and the ‹group› header.




The group opcode is used together with off_by to make something monophonic.

For example, the flute is by nature a monophonic instrument, so if a flute were recorded with one microphone and had one set of samples, it would make sense to set all its samples to have one group. A guitar is polyphonic, but each string is monophonic, so a six-string guitar would naturally be split into six groups - one per string. In these cases, the group number will be equal to the off_by number.

This is also commonly used with hi-hats - this is an example of where things can get more sophisticated with a large number of groups involved, as it's possible to set more closed hi-hat sounds mute more open ones, but not vice-versa, and it's also quite possible that there are separate close mic, overhead and room samples.

group and off_by can also be used in other contexts where one sound should cause another to stop but enforcing monophony is not the goal - for example, a crash cymbal doesn't need to be monophonic, as allowing the sound to build up is reasonably natural, but if we wanted to implement a cymbal choke, then the crash sounds would be in one group, the choke samples in another.

Practical Considerations

The actual minimum and maximum values are not currently known. Some players will treat numbers outside a certain range as equivalent to group=0, and ARIA/Sforzando will also do this with text strings. The behavior of non-integer numbers is also currently unknown. This makes it possible to use an extremely large number for one group, but it's obviously not recommended.

Name Version Type Default Range Unit
group SFZ v1 integer 0 -2147483648 to 2147483647 N/A

Category: Instrument Settings, Voice Lifecycle