key is equivalent to using lokey, hikey and
pitch_keycenter and setting them all to the same note value.
Because of this, it is a very useful and convenient opcode for instruments which
do not need to spread a sample across multiple notes.
That means most chromatically sampled instruments or drum kits.
key values can be specified in MIDI note numbers (0-127) or note names
(IPN Standard). Numbers generally are better to use for getting the SFZ to
behave the same in all DAWs.
These two conventions will yield the same key mapping:
key=72 or key=c5
Both are also equivalent to:
lokey=72 hikey=72 pitch_keycenter=72
|integer||lokey=0||0 to 127|
|hikey=127||C-1 to G9|