One evening in 2006, Joel Rosenberger was teaching a lesson on podcasting, when it occurred to him that it might be fun. So he plugged his low-end digital piano into his computer, and started recording music. Hymns, of course. He had been improvising and arranging these old melodies for years. Then the e-mail started arriving... from around the world... kind words, requests for sheet music and CDs, permission to use his work. Several years and several projects later, Joel continues to co...