There are many ways that you can do this and all of them depend on the type of picture you have. You could take your favourite song and make it into an mp3 file with iTunes or Audacity. You can then open the photo in Photoshop or Paint, add a blank layer below the image, and use something like Gimp if you’re using paint.
Doesn’t work? Takes too long? Don’t want to take your time learning? Here’s another way. You may have come across this question at some point: “How can I add music to a picture?” The answer is quite simple. You simply need to go on YouTube and find the song you want, then copy the URL of that video into your preferred image editing software. Once you’ve done that, select where in the photo you want the music to start playing from and set how long it should play for (if there’s a pause between tracks).
You may have seen this effect on a photo or two before. You upload a picture, you add some music to it and then the app spits out your finished product with the music synced up perfectly to every second of the video. The best part is that there are so many free apps for you to use! Some people prefer Shazam while others like Soundcloud. If you want something more specific, try Vimeo’s new Music Videos or Google alternatives. The process itself is actually very simple.