THIS REQUIRES
OpenIV
Understanding How To Operate 'OpenIV'

https://www.gta5-hub.com/tools/openiv

That's about it.

Instructions
Step 1 - If you haven't already, Open and Set up OpenIV
Step 2 - Follow this path: x64/audio/sfx/INTERACTIVE_MUSIC.rpf/
Step 3 - Turn on Edit Mode (Click the button on the top labeled 'Edit Mode')
Step 4 - Click red 'Show in "mods" folder' button
Step 5 - Drag 'wdy_vinegar_tits.oac' into the OpenIV window.
And you're ready to go.

The MIDI File in this video was originally composed by 'threebuddies' and modified by Me. You can download the original midi file from the video he uploaded showing off the midi file.

Most Interactive Music in GTA 5 is comprised of multi-track tracks. Because the game is a progression style game, some tracks play over others to form a complete song. Giving an atmosphere to the game.

I decided to use OpenIV to extract an Open Format version of one of my favorite tracks in GTA 5, and I took my favorite MIDI File, split it up into different MIDIs to make different tracks and added them to the different tracks in the game.

The original track is Vinegar Tits by Woody Jackson. The MIDI file I used is Sonne by Rammstein.