Info from Wikipedia
T.T. the Bear's began in 1973, opened by New Hampshire native, Bonney Bouley, and her boyfriend at the time, Miles Cares, as something of a dive bar, originally located on the corner of Pearl and Green Streets, around the corner from its final location. They closed it briefly in 1978, only to reopen at a new location, 10 Brookline Street, in Central Square, in 1980, originally as a restaurant; due to back taxes, Ms. Bouley filed for Chapter 11 bankruptcy, then changed the format to a full-time music club in 1984. T.T.'s helped define Central Square, along with The Middle East and, across the street, Manray.

TT's had a capacity of only 300 patrons, which contributed to its intimacy between performer and audience. The club's name originated from the need to be unique, to not have a name like any other establishment; the owners considered their own names, Miles & Bonney's; eventually they decided to name it after their pet "Teddy Bear"-style hamster, who was nicknamed Tough Teddy, hence they settled on T.T. the Bear's Place.