Here's the source code of SID 2 Gumby.
It contains all the songs that were already posted in this thread: http://www.atariage.com/forums/topic/199103-teaser-sid-2-gumby/ plus five more songs:
Thing On A String
One Man And His Droid
The Master Of Magic
Sources are under the GPL3 license. The ADSR code is more or less the same as was used in atarisid3, so if you are going to patch other songs to play with this player, you might need to patch writes to sid's CTRL registers, too, if the player toggles the gate bit off/on in one frame, otherwise it goes by unnoticed by the ADSR code and the channel will fade-out quickly.
Included is the assembler, all .xex binaries, a script to build all tunes at once and all patched (and sometimes relocated) sid files.