Optionalclipthe engines to try, by registered name (or gm-soundfont / builtin for the internal path)
OptionalnotesMIDI notes played for each program; 48, 69 and 84 when omitted
Optionalprogramsprograms (0 to 127) played on channel 0; a spread across the families when omitted
OptionalsampleOptionalsilenta note whose peak stays under this is silent; 0.002 when omitted
Optionaltolerancehow far the strongest partial may sit from a harmonic of the note, in cents; 50 when omitted
Optionalunpitchedprograms whose sound has no pitch to check (sound effects, percussion); 112 to 127 when omitted
the share of samples at full scale that counts as clipping; 0.001 when omitted