Amir bin Sa'd al-Bajali (may Allah have mercy on him) says: I was present with Sayyiduna Thabit bin Wadi'ah and Sayyiduna Qarazah bin Ka'b al-Ansari (may Allah be pleased with them both) at a wedding where singing was going on. I spoke to them both about it, and they said: "Permission has been given for singing at weddings, and for weeping over the dead without wailing."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14692