Summarize the following:
Tap the YouTube app icon, which resembles a red-and-white YouTube logo on a white background. Doing so opens your YouTube home page if you're logged in. If you aren't logged into your account, select your account (or enter your email address) and enter your password when prompted. It's at the top of the screen. Tap the video you want to upload to select it. It's a musical note icon at the bottom of the screen. On Android, this note is in the top-left corner of the screen. This is below the video's preview at the bottom of the screen. Skip this step on Android. Scroll down until you find a song you'd like to use, then tap the song to select it.  You can preview a song by tapping its "Play" button on the left side of the song's name. On Android, tap the + icon in the bottom-right corner of a song to select it. It's to the right of the song's name. You can lower the audio track's volume in order to let through your video's original audio by tapping and dragging the slider at the bottom of the screen to the left. It's in the top-right corner of the screen. Skip this step on Android. Enter a title and description for the video, then tap UPLOAD in the top-right corner of the screen. Your video will begin uploading with your selected audio included. On Android, you'll tap the blue "Send" {"smallUrl":"https:\/\/www.wikihow.com\/images\/2\/2e\/Android7send.png","bigUrl":"\/images\/thumb\/2\/2e\/Android7send.png\/30px-Android7send.png","smallWidth":460,"smallHeight":460,"bigWidth":"30","bigHeight":"30","licensing":"<div class=\"mw-parser-output\"><p>I edited this screenshot of an Android icon.\n<\/p><p>License: <a rel=\"nofollow\" class=\"external text\" href=\"http:\/\/en.wikipedia.org\/wiki\/Fair_use\">Fair Use<\/a><br>\n<\/p><\/div>"} icon in the top-right corner of the screen.

Summary:
Open YouTube. Tap the "Upload"  icon. Select a video. Tap the "Music" tab. Tap Add music. Select a song. Tap the "Tune"  icon. Adjust the audio saturation. Tap NEXT. Publish your video.