If it's a one drive unit, then yes.

/dev/hda4 is the first (only on a single drive) music partition. For some reason I don't recall, they first try to mount it as a Reiser-filesystem (which it isn't, it's ext2), then it does get mounted as ext2.

/dev/hdc4 is the second music partition - only present on 2 drive units. So on a 1 drive unit it can't be found, hence the error.