Here is the full list of all 11 Audio Beats trophies - there are 5 bronze, 5 silver and 1 gold.
Complete one song at advanced difficulty,and get level S.
Complete two songs at advanced difficulty,and get level S.
Complete three songs at advanced difficulty,and get level S.
Complete four songs at advanced difficulty,and get level S.
Complete five songs at advanced difficulty,and get level S.
Complete one song at extreme difficulty,and get level S.
Complete two songs at extreme difficulty,and get level S.
Complete three songs at extreme difficulty,and get level S.
Complete four songs at extreme difficulty,and get level S.
Complete five songs at extreme difficulty,and get level S.
Complete all songs at all difficulties,and get level S.