No, you can't load your own tunes from the Music Composition mode into Nintendo Music. (Though that would be awesome.)
It's Super Mario's 40th anniversary, and one of his early creative works is now available for Switch Online subscribers in two ways.
Mario Paint (1992) has been added to the Nintendo Switch Online Super Nintendo game library, as well as the soundtrack being added to Nintendo Music. The game supports the Switch 2's mouse controls, as well as USB mice on the original Switch.
The activities for the creator include freehand drawing, stamp creation, rudimentary animation, and music creation. A couple of minigames including the famous "Gnat Attack" are also in the package.
