From what I understand, it is looking like the FFVIII theme is gonna be the "Tribute To The Trio" or something along the "tre-theme"....I am sure the official announcement is coming soon.....
Off the top of my head... Rush, Primus, Cream, Jimi Hendrix Experience, The Police, Gov\'t Mule, ZZ Top (Cheap Sunglasses???), King Crimson (at least one incarnation), Band of Gypsys
Of course there are bands that are an instrumental trio (lead singer not included): Black Sabbath/Ozzy Osbourne, Pantera, Tool, The Doors, Van Halen, Alice In Chains, Red Hot Chili Peppers, Rage Against the Machine
Correct me if I\'m wrong... I am both drunk and a youngster listing bands WAY before his time.