Is one who listens to music prevalent everywhere sinful? And is he obligated to denounce it? And is saying "May Allah guide you" considered a denouncement? And is it obligatory to denounce every time a colleague's phone rings with music, or is once sufficient?

Listening to music and installing it on devices is forbidden and a reprehensible act. This is indicated by the Prophet's (peace be upon him) saying: "There will be among my ummah people who will permit illegal sexual intercourse, the wearing of silk, the drinking of alcoholic drinks, and musical instruments [ ma'azif ]..." So, ma'azif are forbidden, and their being coupled with fornication and alcohol confirms their prohibition. The sin of listening to ma'azif falls upon one who intentionally listens to it, not upon one to whose ear it reaches unintentionally. This reprehensible act must be denounced by hand, tongue, or heart, whenever the reprehensible act is found and it is possible to denounce it, as long as the denunciation does not cause hardship to the one denouncing it or result in the loss of a more important benefit. And the statement of the one forbidding the reprehensible: "May Allah guide you" is a type of denunciation if it is understood to express objection and displeasure.