The live jazz/blues/surprise-genre music is just one reason Vancouverites love the Libra Room. East Vancouverites really love the Libra Room because it is open later than most of he other establishments on the drive. The food and drinks are reasonably priced, but the atmosphere is a bit more fancy than many of the other places on The Drive.
If you like live music, and if you like staying up late, this is a great place to stumble into after a late-night movie at The Rio, or after the place you were at before has closed. The music can sometimes be pretty loud if it is live, so it's not the best place for conversation (great for rocking out/avoiding conversation).
If it's summer, and you're walking by the Libra Room at the time of a performance, you can often get a pretty good view from the street.