Hi Murray --
Glad to hear that you're giving this a try!
Yep, you're right. The recorded notes must match the chord root and chord type (NTR/NTT).
Most folks use CMaj7 for the chord root and type.
Extra credit: It's OK to use a different root or type as long as the NTR/NTT info matches exactly.
Double extra credit: Guitar parts in many Yamaha styles don't worry about the chord shape (i.e., choosing notes to correspond to strings). They set the NTR to "Guitar" and let the guitar transposition tables work out the rest. Of course, this is an SFF2-only (SFF GE) feature.
Hope this helps -- pj