Bands With No Guitarist or No Bassist
Not every band needs a guitarist or a bassist. These rock and metal band's certainly don't.
Van Canto
10 Non-Metal Covers of Metallica Songs That Still Rule
Taking the 'metal' out of Metallica.
Metallica “Battery” Cover Using Voices And Drums
I don't know if you'd call these dudes(and chick) metal beatboxers, but what comes out of their mouths is amazing. Check out their full cover of Metallica "Battery" using on their voices and drummer.