They fit into my list of great singers with bad voices. Others being:...my vote goes to dylan. seriously. the man brings incredible character to a lyric, and a melody.
another under-appreciated singer is mick jagger, and for the same reasons.
Neil Young (Kermit the Frog)Neil Young (whiney)
Tom Waits (the baddest of the bad)
Randy Newman (yodelly)
Joe Cocker (Captain, we're breakin' up!)
Johnny Cash (wobbley)
I give them all 100% on delivery.