Bop-bop boo-boo-boom bap-bap-bap traka-traka-track, dun-dun! It is 8 p.m. on a Thursday night in Chicago and you are walking down Division Street. You hear the sound of bomba drums and chanting coming from a storefront in a hundred-year-old building, a three-flat with bay windows, trimmed with ornate brown limestone moldings and other architectural features characteristic of the period when the former Czech dwellers of the neighborhood built it. Today's residents call the street "Paseo Boricua" (Puerto Rican Promenade). Inside, a crowd of fifty people enjoy a bombazo (a Puerto Rican bomba jam-session). The walls are decorated with a Puerto ...