I just happened across your query. Earl Kelly, the soloist in the concerto, was one of two or three top piano teachers in Akron, Ohio. I took piano and private theory lessons with him in high school. He was a longtime piano student of William Becker and went to Cleveland for lessons with him and with Becker's teaching assistant, a woman named Hazel Hart. I can't tell you anything about Becker as composer but Kelly told me that Becker was a celebrated piano student of Xaver Scharwenka and that Scharwenka treated him to a champagne supper after Becker's European debut recital. Legends, legends ...