I'm trying to remember the name of the composer who started out in the drinking taverns?

As soon as I read your title I instantly thought of Henry Purcell. He was noted for his tavern songs and catches as stated in this review of such music as sung by the late Alfred Deller:

http://www.horntip.com/mp3/1600s/1600s--1958ca_tav...

Your title suggests that he hung out in taverns which inspired him to write such music, which may or may not be true. He did write some other wonderful, high-minded compositions as well....particularly all those odes to members of the royal family and several delightful stage productions including "King Arthur", "The Fairy Queen" and "Dido and Aeneas"

A lot of classical composers are known to have played in taverns and brothels over the centuries during their young years (Schubert, Satie, Debussy, etc.) but Brahms (1833-1897; http://en.wikipedia.org/wiki/Brahms ) is probably the one who comes closest to the description you give (though born some 138 years after Purcell's death...).

Best,

Raymond

Edit Add: Or maybe this guy:

- Carl Michael Bellman (1740 - 1795; 45 years after Purcell)

http://www.worldliteratureforum.com/forum/archive/...

http://en.wikipedia.org/wiki/Carl_Michael_Bellman

As stated many, many composers were fueled by alcohol.

... Scott Joplin got his (under age) start playing piano in a brothel, though.

Knowing musicians, and being one myself, I should think that description could apply to any number of people.

You are gonna have to be a lot more specific.