Imam al-Shafi'i (may Allah have mercy on him) said: "The testimony of neither of them is admissible, and that is because it is part of the disliked idle amusement (lahw) that resembles falsehood; for whoever does this is regarded as foolish and lacking in decency (muru'ah), and whoever accepts this for himself holds (his honour) lightly, even if it is not clearly forbidden."
Abu al-Sahba' narrates from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) concerning this saying of Allah Almighty: "And among the people is he who buys idle talk to lead (people) astray from the path of Allah" [Surah Luqman: 6], that he said: By Allah, what is meant by it is singing.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 21003