here are very few places in Boston where you have to dodge a trumpet player to get to the restroom. Wally’s is so small and worn it feels like your grandfather’s basement—that is, if your grandfather was a jazz purist. The inevitable black-and-white photos of jazz legends decorate the jazz club’s weathered brick walls, and beers and specialty drinks are listed on a chalkboard that looks like it was written when Miles Davis was in his prime. Wally’s is always packed (it’s open, with live music, every night of the year), but rarely uncomfortable, and there’s never a cover. The best way to find your groove is to order a bottled beer and stand shoulder to shoulder with the jazz-crazed regulars and Berklee students who make up most of the crowd; a table will open up before you reach the bottom of the bottle. Every night of the week explores a different theme, with jazz always king. Tuesday night funk/fusion with Wally’s Stepchildren 1 (or Wally's Tuesday Funk, a.k.a. WTF) is the best way to wash down the midweek blues. Wallace