According to IMDb there are 12 titled episodes plus the Pilot, so 13 episodes in all of 26 minutes each. The Varese Goldsmith at Fox box had roughly 16 minutes of Goldsmith's contribution, taken from three episodes: the Pilot, Anna's Romance, and The Chimes. So Goldsmith wrote (at least) three. According to this Jon Burlingame article Richard Shores also scored three episodes.
http://www.filmmusicsociety.org/news_ev ... 22004.htmlI don't know if any other composers wrote original music for the show besides those two, but I suspect there were occasional original bits and pieces written for episodes with largely tracked scores, as happened occasionally on shows like Star Trek or from Fox, the Planet of the Apes TV series (remember how LLL's complete release featured original music from more episodes than expected).
Yavar