La Pesada

Originally intended to be the backing band for Billy Bond (as Billy Bond Y La Pesada Del Rock And Roll), La Pesada was a collective formed in Buenos Aires in 1970, featuring musicians like Pappo, Luis Alberto Spinetta, Javier Martínez, David Lebon, Vitico, Héctor "Pomo" Lorenzo, Black Amaya, Poli Martínez Luis Gambolini, Nacho Smilari and Cacho Lafalse, among others.
By 1972, the line-up of the group became more or less stable, with Claudio Gabis and Kubero Díaz on guitars, Alejandro Medina on bass and vocals, Jorge Pinchevsky on violin, Isa Portugheis and Jimmy Marquez on drums, plus Billy Bond on vocals and production.
Some of the aforementioned musicians (Medina, Gabis, Pinchevsky) would also record solo albums with La Pesada as backing band.
It's live perfomances were controversial and often attracted police attention and difficulties resulting in a perfoming ban by the end of it's life cycle, but it remained studio active.
Disbanded in 1974 after a terrorist bombing led core members Billy Bond, Claudio Gabis and Alejandro Medina to emigrate to Brasil.