Never forget that Hebrew cantillation was the root of Christian chant later codified by Gregory. In short it is the most ancient a cappella to which we have access. It is not surprising that New York City, with strong orthodox communities in the midst of the neighborhoods which are the doo-wop centers of the world, would have a new emerging Jewish synthesis. Beat'achon combines traditional chant with doo wop elements and harmonies to update an ancient tradition. It is a fascinating historical development.