Hi and welcome!
I'm not an expert on BSG music, at least not as much as the other moderators around here, but I did a little research. The episode should be "Valley of Darkness" (Season 2 Episode 2), and I found this note on the
Battlestar Wiki page:
"The music that plays in Kara Thrace's apartment and again during the closing act of the episode is Metamorphosis One, composed by Philip Glass. It is from Glass's 1989 album Solo Piano."Hope this helps.