Allmusic

AllMusic  (previously known as All Music Guide or AMG) is an online music guide service website.  AllMusic was launched in 1991 by Michael Erlewine of All Media Guide (later became All Media Network).  The aim was to  “[compile] discographic information on every artist who’s made a record since Enrico Caruso gave the industry its first big boost”.  Its first reference book was published the following year.   (More from Wikipedia)