Dave Matthews Band is from the US and has been around for over a decade. Pretty popular with college kids, hippies, people who like jam bands like Greatful Dead, Allman Brothers, Phish, Widespread Panic, etc...
Scouser- try picking up one of their live albums, maybe there are 3 or 4 and are more representative of their melodic style and long jams. I kinda think of it as classical music except its rock/jazz.
Ocean11- Santana`s Supernatural is an awesome CD... a really interesting mix of musicians, eh? Santana`s concerts are really good!
Free sites? Dont know of any anymore.