note: Not all musicians are going to have each and every one of the checklist, but be wary of any you don't have.
As an example, Musician Y "doesn't do social media"... and Musician Z does. Musician Y is a famous musician who has been out there for years and knows just about every club owner in town. Musician Z is an up and coming start who works social media quite well, effectively promoting himself using many a wide variety of platforms. The needs of these two players will be very different and each has some assets to offer the other.