I need help identifying a children's book I remember reading years ago.
Plot: the king announces a contest for his daughter's hand in marriage. The first person to pass through the enchanted forest and arrive at the castle wins. The forest is filled with creatures that try to lead people away by mimicking various sounds. To help, the king will play his music from the castle tower (I believe it was 2 or three times a day?). The contestants must then try to recognize the king's music over the music of the creatures to find their way. Contestants are allowed to bring one other person with them; most choose strong men or soldiers.
A young man takes the king's son with him; he has the king's son play his own music while they travel so that when the king plays his music, he'll be able to recognize it and find his way to the castle.
I had read this book years ago, but have not been able to identify it. Also, there are very obvious Christian themes to this book. It is not a chapter book as far as I can recall; I believe it followed a format of full-page picture on one side and full-page text on the other for I believe at least 10 pages.
Any idea which book this is?