We can probably agree that you need to be proficient with your instrument to play in a band. What does being "proficient" or "good" with your instrument mean exactly? What other qualities/skills etc., are needed to play in a band?
stay in time with drums and other instruments, and generally play wat u need to play making it sound good
you dont need to be a good player to be in a band, just try to be in one with people around your skill level
dont show off in band practice, stick with what needs to be played. must be able to work with other members and u should have similar music tastes