Ext3 is ext2, just with a journal file added. At any point one can stop using it as ext3 and revert to ext2 (or the other way around) and everybody is still happy. Very convenient. I'd be particularly suprised if the player software even knew or cared significantly about it, other than perhaps whatever scheme is used to "recognise" the music partitions (use f/s "labels"?).

Newer distributions include userland support for fstype="auto", where if the kernel has ext3 support it mounts as ext3, otherwise as ext2. Very useful for us kernel developers as we see-saw between Alan's (with ext3) and Linus's (no ext3) versions.