ok, here are teh list of steps you have to do.
1.find your MP3 or audio
2.open it in audacity
3.cut down to the part you want
4.ALWAYS KEEP IT 30 SECONDS AND UNDER, IT WILL TAKE PEOPLE TO HAVE LONG DOWNLOADS TO YOUR SERVER
5.go to the sides and click the down arrow button
6. click split stereo track
7.go on both they down arrows on both of those things, and change them from "Left" and "Right" to "Mono" on both of them.
8.go up to file-->export as OGG VORBIS-->save the name like this, EX:"Yoshi_Island.ogg" notice the underscores(these things _ ) and use those for spaces, and always put .ogg at the end
9.when you search for it after you save it, it will not have the ".ogg" behind it.
10.close audacity
11.go find the OGG
12.drag it to desktop (unless it was saved there)
13.go to Start-->My DOcuments-->Blockland-->Add-Ons-->Music, and put it in there
14.open Blockland
15.go to the "Start A Game" menu
16.gointo "Music Files" and find the song, and check off the box next to it
17.Start the game
18.rock out!!!!