Is the chanting of "La ilaha illa Allah" (There is no god but Allah) and the invocation of blessings upon the Prophet in a wedding song, with loud music playing over it, considered a degradation of God, an act of disbelief (kufr), or a sin, or is it merely a matter of groundless misgivings (waswasa)?

Listening to songs accompanied by music is forbidden and one must repent from it. Its prohibition intensifies if it is mixed with dhikr (remembrance of Allah), as this contradicts the glorification of Allah's sacred ordinances. Nevertheless, listening to songs or music accompanied by the remembrance of Allah, unless it is done in a manner of disdain or contempt, does not constitute kufr (disbelief) for either the listener or the singer. What some imagine to be kufr is merely a waswasah (whispering from Satan) that should be ignored. One must avoid listening to songs and music and distance oneself from the waswasah of kufr.