I've been trying to track down this movie with no luck but have discovered there are two versions. The character designs are pretty similiar.
All I can go by is a feint memory of old man dying, monkey dying, maybe dog died too. I don't know about the dog dying but it was that kind of story...
Anyway I also remember Remi the lead character sings a song with the lyrics "nobody's boy, nobody's boy..." while playing his harp. That's all I remember.
anime series originally released in mid-70s re-cut into a movie.
Hopefully someone knows which version I saw and if it's available.