One of the most unique traits of jazz music over the past century has been its ability to evolve. It’s one of the most difficult music genres to define because it is constantly in a state of flux to match the times. It’s that stylistic elasticity that has made it possible for Alexander Claffy, a bass player embedded in the New York City jazz scene, to release a new genre-blending single that features him branching out to deliver vocals for the first time. The new track “Tassia” features guitarist Kurt Rosenwinkel and is the first offering from Claffy’s sophomore EP, which is due out this fall.