I can’t comment on the post 2000 Pumpkins but I’m pretty sure Billy did most if not all the lead duty in their prime years. Every music video or live clip I’ve seen has him soloing. For example: http://www.youtube.com/watch?v=XPOv3iyy1qo
Peter Frampton, with the Herd and Humble Pie, as well as a soloist. Glenn Frey and Joe Walsh of the Eagles share guitar duties and both sing lead vocals on various songs.
There’s wasn’t always one clear lead singer or one clear lead guitarist in the Doobie Brothers… but at different times, Patrick Simmons could claim both titles.
In their prime, Chicago had three guys sharing lead vocals. Lead guitarist Terry Kath was one of them- he had the deep, gruff voice featured on songs like “Make Me Smile.”
I have to admit I’m more a radio listener, and have no idea who anyone is, really. So I have a small question: Do any of these guys play lead and sing lead simultaneously? I don’t mean the same song, I mean at the same time. If so, I would love to hear what you think is the best example.
I know that, even when I play piano, I have a lot of trouble playing two different melody lines at once. I’m always playing rhythm while singing, and filling in other lines during rests.
I thought about Carl but decided he wasn’t the best example, since he didn’t do many lead vocals (and certainly wasn’t a frontman) in the early days, when the Beach Boys were a performing band playing all their own instruments. He really came into his own as a vocalist on less guitary, more studio-oriented tracks like Good Vibrations and God Only Knows.
Leads usually aren’t played much over vocal parts as general rule, just to keep from stepping on them (not full fledged solos, anyway), it’s more about fills and licks during vocal parts, even with a separate guitarist, but there are singer/guitarists who lick quite a bit as they’re singing – SRV, for instance, or Jimi Hendrix. Hendrix did it constantly. He was ridiculous with it.