Adds You're Gonna Need A Bigger Ukulele from Risk Of Rain 2 in Payday 2 as a custom track.

Preview: (Time placements may be a little off, due to Youtube stuff.)
Stealth:
https://www.youtube.com/watch?v=ysPtBjY8o_A

Control: 1:20 - 1:24, (intro,) followed by 1:25 - 2:27 (loop)
Anticipation: 0:09 - 0:12, followed by 0:26 - 1:11
Assault: 2:28 - 2:31, (intro,) 2:32 - 4:08 (loop)
https://www.youtube.com/watch?v=r2JeL1ibBI0

Extract into assets/mod_overrides.