Listening to music is haram, whether in Ramadan or at other times, but it is more forbidden in Ramadan, and is a greater sin. For more, please see the detailed answer.

Sleep does not invalidate fasting, but for a fasting person to spend most of the day asleep is a kind of negligence on his part, especially since the month of Ramadan is a special time and the Muslim should strive to benefit from it by reading Quran a great deal, seeking provision and acquiring knowledge.