What would cause the music to scramble but not the other sounds? Past experience tells me a bad rom. If so, which one is it? Thanks in advance for any help.
Phoenix uses a melody chip (MN6221AA) for the music, it was stated in the datasheet that a possible use for it was as a door bell. These can still be bought for around $10.
Yes, it is a melody chip rather then a sound chip, with a few components you can play a few simple melodies and in the 70s it would have made quite a modern doorbell. There are other chips in the MN6221 which play different melodies so make sure you get the right one