Steve Vai – lead vocals, guitar, all other instrumentation (except where noted), arrangement, engineering, production
Devin Townsend – lead vocals (tracks 4, 9)
Will Riley – keyboard (track 14)
John Avila – bass (track 2)
Stuart Hamm – bass (track 3)
Fabrizio Gossi – bass (track 14)
Chris Frazier – drums (track 1)
Greg Bissonette – drums (track 2)
Deen Castronovo – drums (tracks 3, 5, 7, 11, 12, 15)
Mike Mangini – drums (tracks 8, 9)
Robin DiMaggio – drums (track 14)
C.C. White – background vocals (tracks 12, 17)
Tracee Lewis – background vocals (tracks 12, 17)
Miroslava Mendoza Escriba – background vocals (tracks 12, 17)
Kimberly Evans – background vocals (tracks 12, 17)