Is Commenting on Music Videos Allowed?
Question

What is the ruling on writing words of religious advice, adhkar and sending blessings upon the Prophet (blessings and peace of Allah be upon him) in the comments sections and reactions for music videos on YouTube?
Praise be to Allah.Watching videos with music: Permissible for Muslims?
Regarding videos in which there are women singing, or men singing with the accompaniment of musical instruments , or that contain indecent words, it is not permissible to listen to them or watch the videos, or to share their links, or to like them, because all of that involves falling into what is haram or helping in that. Allah, may He be exalted, says (interpretation of the meaning): {And cooperate in righteousness and piety, but do not cooperate in sin and transgression. And fear Allah; indeed, Allah is severe in penalty.} [al-Maidah 5:2]
The Prophet (blessings and peace of Allah be upon him) said: “Whoever calls to guidance will have a reward like that of those who follow him, without that detracting from their reward in the slightest. And whoever calls to misguidance will have a reward like that of those who follow him, without that detracting from their sins in the slightest.” Narrated by Muslim (4831).
Can Muslims comment on music videos?
Comments on these videos are of various types:

Praising or liking the video; this is clearly haram.
Comments that have nothing to do with the video, such as giving some religious advice, or sending blessings upon the Prophet (blessings and peace of Allah be upon him). This is also haram because it fails to denounce evil, and is deceiving the sinners in a way that is not denouncing them and by increasing the number of comments they get. Moreover, by looking at these videos, a person is exposing himself to temptation by seeing the videos and what appears next to them. The safest way is not to go to YouTube except when absolutely necessary.
Denouncing evil by explaining that this music is prohibited. This may be done if there is the hope that the original poster or viewers may respond to him, because he mentions the evidence for the prohibition or the words of scholars concerning that. This is good, and it comes under the heading of denouncing evil and advising people. But he should not deliberately look for videos to denounce them; rather this may be done if he comes across a video, on condition that he does not listen to it or watch it.

If he thinks it most likely that his words will not be of any benefit, as is usually the case in such matters, then it is a waste of time, and posting a lot of comments will promote the video without him realizing it.
Please see the answer to question no. 241926 .
The best is to close this door completely, because the last scenario, which is the scenario of denouncing the evil – assuming that his words will be of benefit – is fraught with danger, and the one who does that may not be safe from viewing haram images or being drawn into listening to or watching that which is haram. If he focuses instead on posting good videos or commenting on them and promoting them, that will be better for him and safer.
And Allah knows best.