Imam Nawawi said with commentary by Muhammad Shirbini khatib : it is not prohibited to dance
This is according to hadith in Bukhari that the prophet SAW stood before aishah to screen her from view so that she could observe the Abyssinians sporting and dancing
Reagarding singing:
Hadith - Sunan of Abu Dawood, #4909, Narrated Abdullah ibn Mas'ud
Salam ibn Miskin, 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 (peace be upon him) say: Singing produces hypocrisy in the heart.
http://www.turntoislam.com/forum/showthread.php?t=8699&highlight=music