Guitar, bass, keys, drums, and vocals (one of the 4 sings + plays instruments). I think 4 is the ideal number for the types of rock I like and I much prefer keyboard/piano/organ to no keyboard.
There were some formations that could’ve worked themselves on the list, but that would’ve made it too long.
- bass, two drums, two guitars, two keyboards (Allman Brothers)
- bass, drums, 2 guitars, 2 keyboards, sax (Dire Straits live )
- bass, drums, 2 keyboards (occ. guitar), wind/keyboard (Supertramp)
- bass, drums, keyboard, guitar, drums + vocal (Genesis live)
The list is endless.
I prefer vocalists that play an instrument, although those faking it with a rythm guitar at 0.01 volume aren’t fooling anyone so I’d rather they just sing.