Add Music to a Video Online - Free

Music under speech has one job, which is to be noticed and not listened to. The usual mistake is mixing it at the level it sounds good on its own; under a voice it needs to sit far enough down that you would struggle to hum along. If a sentence is hard to follow on laptop speakers, the music is too loud, and laptop speakers are the right thing to check on because that is what most people watch on.

Music with no speech under it is the opposite problem: at the level that works under a voice it sounds like a mistake, so a track carrying a montage on its own wants to be much closer to full.

The other half is rights. A track you like is not a track you can use, and platforms match audio automatically: the consequence is usually a muted video or a claim on the revenue rather than a letter, but it lands after you have published. Music licensed for video, or music you made, is the only version of this that does not come back.