I am very new to the bass and am just starting to feel comfortable playing with some friends. I was wondering if there were any excercises I should be working on to improve my playing. I know this is kind of vague but anything anyone might suggest for a beginner would be much appreciated. Also, who are bassists I should be listening to? I have a Black Market by Weather Report with Jaco Pastorius and I enjoy both Les Claypool and Mike Gordon. Any bass playes I should be listening to?