Human: How do I put music onto videos on my iphone? Assistant: 
Put Music Onto Videos on iPhone or iPad
1. Open the iMovie app.
2. Tap Create Project.
3. Select Movie.
4. Select your video.
5. Tap Create Movie.
6. Tap the white "+" icon on the left.
7. Select Audio, and select a category.
8. Select the track you want to add.
9. Tap the "+" next to it.