Who is Father Wasner from The Story of the Trapp Family Singers and what is their importance?

Maria doesn't provide much information about the priest. She does praise the priest who turns the family singing into a profession. However, he does live with the family for many years, if not the rest of his life, and the reader gets very little information on him. One knows that he escapes with the family, travels, and participates in all daily activity, but little insight into his character is given other than his role of impressive musician. His is a wooden character mentioned when needed and immediately removed.