You can run as many campaigns as you would like for the same song. Once you upload a song, you will be able to select it for additional campaigns when you create new campaigns.
When you create multiple campaigns for the same song, you can target different demographics, have a different message, select a different call to action, and have different budget settings.
Please note: When you create multiple campaigns for the same song, if you edit the Song Level targeting/attributes on Step 2, the changes will be made for all campaigns that include that song. You can have different Song Level settings for multiple campaigns that include the same song.
If you want to have different Song Level settings, you will need to upload your song again, and change the settings on that instance.