Musician automatically creates parts under the following circumstances:

1.When you import a MIDI file, one part is created for each track, except for tracks with no notes.  Said another way, one part is created for each staff in the score.  Also, a conductor's part is created, which has all of the staves.

2.The Prepare Part Wizard automatically creates the Sing-Along part, Easy Notes part, or Fake Book Lead Sheet part.

3.The Split Hand command automatically creates a new keyboard part with the pair of right- and left-hand staves.

4.The Split Drums command automatically creates a new drum part has all of the split one-line percussion staves

5.The Prepare Piano Reduction command creates a single new keyboard part.