http://www.youtube.com/watch?v=_V5s4R8rQ84

Sahih Bukhari Volume 5, Book 58, Number 268: 

Narrated Aisha: That once Abu Bakr came to her on the day of 'Id-ul-Fitr or 'Id ul Adha while the Prophet was with her and there were two girl singers with her, singing songs of the Ansar about the day of Buath. Abu Bakr said twice. "Musical instrument of Satan!" But the Prophet said, "Leave them Abu Bakr, for every nation has an 'Id (i.e. festival) and this day is our 'Id." 

Sunan Abu-Dawud Book 41, Hadith # 4909

Narrated Abdullah ibn Mas'ud(raa) : Salam ibn Miskin(raa), quoting an old man who witnessed AbuWa'il in a wedding feast, said: They began to play, amuse and sing. He united the support of his hand round his knees that were drawn up, and said: I heard Abdullah (ibn Mas'ud) say: I heard the apostle of Allah (SAW) say: Singing produces hypocrisy in the heart.