Use the source file linked below to edit the sounds inside of your BO2. I found that the file below had main menu music and after running the program you can right click the file of choice to replace the sound with any MP3.
HOW TO:
Unzip sound extractor program to a local folder > run Black Ops II Sound Studio.exe >
File > Open > go to below directory and choose the file > (mpl_mus_frontend.SL65.pc.snd is the menu music) > right click to replace with any MP3 of choice <3.
Directory: BO2 File location\sound
File: mpl_code_post_gfx.all.sabs
Original Thread: https://www.itsmods.com/forum/Thread-Release-Black-Ops-II-III-Sound-Studio-1-5-4.html
Source: https://github.com/master131/Black-Ops-II-Sound-Studio/releases
Crab Rave Menu Music if you're lazy: https://drive.google.com/file/d/18sd8qXQGB1NoXB4bcjFsXIB2ysMgI9JM/view?usp=sharing