@ECHO OFF

SETLOCAL ENABLEDELAYEDEXPANSION

set "sourcedir=C:UsersusernameDesktopNew folder"

for /f "tokens=1,2,3,4 delims=_" %%a in ('dir /b /a-d *_*_*_*.mp3') do (

set x= %%d

set y= !x:~1,5!

mkdir "!y!" 2>nul

move "%%a_%%b_%%c_%%d" "!y!"

)
endlocal