well, their's lots of ways to do everything. You could just play a b flat power chord, we've been showing you the bare chord version. The main problem with b flat and lots of other chords is that they don't use any open strings- hence the reson guitarists write songs in E, A, B, etc. Basicly a B flat chord is only an A moved up half a step. Anyway you can think of playing an A, you can turn into a b flat by raising all the notes half a step (one fret).