The
"Instruments" view includes 2 check boxes named
"P" and "S" for each staff. By default, the
"P" box is checked. It means "Play". All the
staves for which the "P" box is checked will play their
notes. Disabling an instrument with this box, you can mute its
notes, for example if you disable the soloist of a score, you can
play it yourself.
The "S"
box means "Solo". By default, this box is not checked.
If you activate it for one instrument, all the others will be
muted. If you activate it for some instruments, they will play
their part and the others will not play. It is an alternative to
the "P" box use. For example, if you work with an
orchestra score and want to listen to some measures with one
instrument only, check the "S" box of this instrument.
Using the "P" box, you would have to disable all the
other instruments to obtain the same result.