Pans are really funny instruments, although I'm a terrible player.
There are 4 typical sizes called (from highest to lowest) Double seconds, Tenor guitar, Double guitar and Tenor bass.
Seconds play solos, guitars strum chords and bass plays, well, the bass.
Here's a site with good explanations :
http://www.rockcreeksteeldrums.com/
There used to be a steel drum ring but I can't find it.