Random observation:
Been gigging in full bands since '87 (and still doing it... gigged last nite in a 6 piece band).
Recently, however, I have also gigged in a 3 piece with BACKING TRACKS. No bassist, drummer, or keyboardist... just a female vocalist, male vocalist on acoustic guitar, and myself on electric guitar.
WAY MORE FUN than I expected!
The mains (minus my guitar of course) are pumped into my monitor... I still play thru my amps (Mes Boogie Mark IV and Marshall Silver Jub) but at a much lower volume (knocked down with a Hot Plate attenuator).
Awesome experience... and the drummer and bassist play perfectly in time lol.