AZ is a Brooklyn, NY rapper, of Dominican descent who got to make his appearance as the only guest rapper on Nas' classic album 'Illmatic' on the song "Life's A Bitch" in 1994. AZ cut his own album a year later, Doe or Die, but due to lack of promotion, the album didn't do as well as other established artists such as Raekwon's "Only Built 4 Cuban Linx" or Jay-Z's debut, "Reasonable Doubt," even though it is considered just as classic as those albums.
It was followed by the sophomore slump 'Pieces of a Man.' It was on par, lyrically, but the beats, mostly handled by the Trackmasters, didn't come through for AZ.
Since his album flopped, he left Noo Trybe and in late 1999 early 2000, he released an independent album SOSA (Save Our Streets AZ). Motown (yes the R&B label) heard his album and was interested in releasing it commercially and decided to give AZ a record contract.
He was supposed to carry them as a serious rap label, but again, due to lack of promotion, his album, 9 Lives, didn't sell as well as he'd liked, though it was critically acclaimed and touched on all aspects, lyrically and musically. His follow up in 2001, Aziatic, sold a few more albums than 9 Lives and is just as great an album as Doe or Die and 9 Lives.
AZ has since left Motown and is rumored to be making an independent album with Nas which is supposed to be titled "Alpha/Omega." Only the future will tell.