Howdy Alan,
You should be able to adjust the volume by using either
1. the Staff control for setting up the staff and entering a numeric value for the volume
or
2. the volume adjustment on your keyboard, as you play along. (I'm not that adept - I always set a fixed volume
)
There is further information in the User's Guide for setting up devices and playing along while MidiNotate plays a song. Use Help/User's Guide, then Search for "play along".
ttfn,
Sherry