I'm sending the patch again, so that it is correctly rebased on the current master.
Here are the two sample files required by the FATE test:
https://0x0.st/Xaw2.aea/boxboy333_house_music_multitrack.aea
https://0x0.st/Xaw_.pcm/boxboy333_house_music_multitrack.pcm
Please let me know if I need to provide anything else.