_arraymusic = ["Pac_MUS1","Pac_MUS2","Pac_MUS3","Pac_MUS4"]
_arraylength = [253,147,600,130]

#loop

_i = random ( (count _arraymusic) - 0.5 )

~1

_music = _arraymusic select _i
_length = _arraylength select _i

playmusic _music

~_length

goto "loop"  