Advanced search technique: Since all of the parodies have the same tune, you can search for the tunefile name.
1) Search for Greensleeves.
2) Go to a standard looking version of the song.
3) Look at the bottom of the listing for the tunefile name, in this case GRNSLVS (yes, it is DOS, with an 8 letter limit)
4) Search for *GRNSLVS. You need the * in front of (never mind why, but you do for tunes)
Happy hunting