I was thinking about Dire Straits the other day and realized something odd- Mark Knopfler was both the singer and the lead guitarist. This seems unusual to me; except for three-piece bands I can’t think of any other notable group in which the lead singer also played lead guitar (that is, full-time, so excluding artists like Prince who often doesn’t even have a guitar in his songs).
Nearly always it seems that the lead vocalist plays rhythm guitar (see Metallica), or even bass (Cream). Even Dave Mustaine, who was a lead guitarist in Metallica, became a rhythm guitarist when he formed Megadeth.
Pink Floyd – Syd Barrett, then David Gilmour
Be Bop Deluxe – Bill Nelson
Mothers of Invention – Frank Zappa (whether he was the lead singer is debatable; I would say he was the lead singer in the later incarnations)
Neil Young & Crazy Horse
Emerson, Lake & Palmer