I've been to the Hammer Museum in Westwood twice for their Also, I Like To Rock series. Imagine tons of displaced westside indie hipsters converging on a museum for an evening of free art, music and drinks. The first time I went, I caught the band Low vs Diamond (love them!) and the second time I saw the band Eskimo Hunter. While the sound quality was lacking, it's a great venue to get up close to the bands and see some art while you're at it.
Concerts are every Thursday in July. Check it out!