Claim: Metal for Muthas I and II, are hard rock and heavy metal compilation albums that were released in 1980; they were reviewed by AllMusic, an online database for songs, music and albums launched in 1991, and created by Michael Erlewine.
Evidence: Heavy metal, hard rock 15 February 1980 (Vol. I) AllMusic (Vol. II) AllMusic AllMusic (previously known as All Music Guide and AMG) is an American online music database. Online database for music albums, artists and songs; reviews and biographies Michael Erlewine 1991; 29 years ago (1991) (as All Music Guide)