Good post, La Signora di Fucile! I'm an old hippie, so most of mine would be rock tunes:

Vito: Bad Company (by Bad Co.)
Luca: Dirty Deeds Done Dirt Cheap (AC/DC)
Sonny: Them Bones (Alice in Chains)
Connie: Janie's Got a Gun (Aerosmith)
Kay: Miss Misery (Nazareth)
Fredo: Simple Man (Lynyrd Skynyrd)
Clemenza: Stranglehold (Ted Nugent)
Tessio: Nowhere Man (The Beatles)
Sollozo: Runnin' with the Devil (Van Halen)
Lucy Mancini: Any Way You Want It (Journey)
Michael: 21st Century Schizoid Man (King Crimson)