Do you have a Google Android or an Apple iOS device?
Both the Google Play Store and the Apple AppStore have a page that lists all your past purchases. Try to find Music Studio in this list, there should be a download button next to it.
If Music Studio is not in this list, you may have used another account (Google Account or Apple ID email address) for your purchase last year. Login with this account into the Store, then the download should be possible.
In general, neither Apple nor Google charge you twice for the same app, as long as you’re using the same account.