Today I happened to attend an Episcopal service because a guest cellist was playing. The cellist is a daughter of a priest who was canon at a major cathedral. She has a masters from Juilliard.

There was no discussion about what she was going to play, or even if she would play, on the hymns and service music.

During the service she played along with the hymns and service music, on the hymns, playing a different part each time from the SATB score in the hymnal.

On the hymn and service music that had only melody. She did not play.

Interesting.