I think it's important honor a performer's feelings about recording. When in doubt, ask. If there's a particular song that is not available on CD or tape, the performer may well offer the opportunity to record that one song at a later time during the weekend. Or not, if he has other reasons for not wanting to be recorded........copyright ? Or maybe the song isn't finished? Or maybe the performer thinks his CD carries the rendition he wants remembered? There could be any number of reasons.