To add onto the list of jam bands... I have to say Dave Matthews Band... they're my favorite.... haha

On to rhythm... I personally believe everyone has rhythm. God gave everyone a heartbeat........ it beats in rhythm. I think it's just that some people can feel that rhythm and move with it where some can't. It's not that they can't learn though. Dancing is a great way to practice rhythm. Or just listening to a song and assigning a hand and foot to each part of the drum beat. Nodding your head to the tempo... most of the time the tempo is set by a bass drum or bass guitar. You should be able to feel that reoccurring beat in a song. Then assign your right hand to double time... slapping your knee twice as fast as you're nodding your head. Then assign your right foot half time... tapping your toe every other beat... This is mainly a beginning drummers excercise... but when it comes to rhythm... drummers have to have the best rhythm of all... Also try to download some jam tracks or some backing tracks to your favorite songs and play along with them... It should help you get the feel of timing in a full band setting.