The Four Imams of fiqh — Abu Hanifah, Malik, ash-Shafi''i, and Ahmad — are agreed that musical instruments (al-ma''azif) are forbidden. The proof is the explicit hadith of al-Bukhari (5590) on the authority of Abu Malik al-Ash''ari: the Prophet (ﷺ) said: "There will appear among my Ummah people who will declare permissible: fornication, silk, wine, and musical instruments (al-ma''azif)." The hadith establishes that ma''azif belong to the same category as fornication and wine — and the wording "will declare permissible" only makes sense if they were originally forbidden. Allah said: "And of the people are some who buy idle talk (lahw al-hadith) to mislead from the way of Allah." (Luqman 31:6) — Ibn Mas''ud said three times: "By Allah besides whom there is no god — it is singing." (al-Hakim, sahih). Excluded from the prohibition is: the duff (a one-sided drum) for women on weddings and at the two ''ids; the chants of the Companions while digging the trench; and the lullabies sung to children. Singing without instruments — if its words are clean and it is not a profession one habituates upon — is differed about, but the safest path is to leave it.