Imaam ash-Shaafi’ee — rahimahullaah — said in al-Umm (6/209),
‘Indeed, music is makrooh (His statement ‘makrooh’ means that it is unlawful, since this is what it meant amongst the early people) amusement resembling falsehood. And whosoever listens to it much, then he is an idiot (safeeh) whose testimony is to be rejected.’