An American Muslim who used to listen to Music and said it used to comfort him asks: Why has Islam forbidden music?
Shaykh Ibn ʿUthaymīn – Allah have mercy on him – replied:
Islam has forbidden music because it captivates the heart and distracts it from remembering Allah. Man was created only to worship and obey Allah the Mighty and Majestic. So if his heart becomes attached to these instruments, i.e. music, this prevents him from remembering Allah the Mighty and Majestic. That is why you find those who become occupied [by music], you can find one of them walking moving his hands as if he is playing music, yes? Because his heart has been occupied with it. Islam wants its followers to always be looking to Allah the Mighty and Majestic (remembering Him and concentrating on Him).
Audio download (with full conversation and incorrect translation!): http://www.sahab.net/forums/index.php?showtopic=143191