-snip-
There is another way, which might be a little more faster.
After uploading your
stereo song/loop file, go to 'Tracks' and go down three to 'Stereo to Mono', click it, then wait for the process to finish. Once it's done (assuming you've already made your loop), export it as a .ogg in the blockland music folder.
An example name: What_Ever.ogg
Will appear as: What Ever (in-game)
(Note: it's only grey colored because I did not have any song uploaded)
