You can add music to a video on your iPhone with the free iMovie app, and select from stock music or your own library. Here's how to do it.

To add your own audio to an Instagram Story, you can either record directly within Instagram by selecting Camera and holding the Record button or use a video editing app like InShot to import and edit ...

Make your own sound on TikTok by adding a voiceover, or recording a separate video for audio purposes.