This is my new project, which adds FLASH FM with all the songs and ethers to the GTA V. Mod is under development.
Installation:
Replace files from the "User Music" folder(in archive) to Documents/Rockstar Games/GTA V/User Music.
Replace "hud.ytd" from archive to mods/update/update.rpf/x64/patch/data/cdimages/scaleform_generic.rpf
Enjoy the music!