DESCRIPTION:
The party music used during Diamond Heist were original tracks by Simon Viklund made before the game, and not really intended for the PAYDAY: The Heist Soundtrack.

You can find these songs on his site at
http://simonviklund.com

I am only uploading them here for those who can't find the songs, but full credit is given to Simon Viklund for these awesome tracks.

The entire PAYDAY: The Heist Soundtrack was made by Simon Viklund.