I don’t know of any LACs that are specifically known for a jazz/blues scene. If I had to find some, I might start by looking into LACs that are noted as being particularly urban, or particularly funky, or both. This would thin it out quite a bit, because many LACs are neither particularly urban nor particularly funky.
Possible candidates might include Occidental (both), Macalester (both), Reed (both), Wesleyan (funky), Oberlin (funky), or Rhodes (urban).