On Last.fm, "Chachi" refers to one of two musical acts:

CHACHI Chachi is an indie rock band from Southern California. Founded by Randy Garcia and Richard Morales, Chachi released their first album "Socially Inept" on February 26, 2009.
Band website: chachi.us

CHACHI CARVALHO Charles "Chachi" Carvalho is an emcee from Pawtucket, Rhode Island. Besides promoting local artists and local hip hop shows he runs his own independent company "Big East Music.