OptionalblockOptionalgainmaster level, 0 to 1; 1 when omitted since a synth owns its own output level
Optionalmaxhard cap on rendered seconds; longer tails are cut
Optionalmutedchannels (0 to 15) whose messages are dropped, for stems and adaptive mixes
Optionaltailseconds of release left after the last message; 1.5 when omitted
frames rendered per call into the synth; 1024 when omitted