Follow instructions at bottom. TO ADD SONG FROM SOUND STUDIO X TO YOUR GAME: Click "See Inside" at the top right. Click the "Play" sprite and follow instructions in the comment. Use D to delete the last noise if you mess up. NEED A REFERENCE FOR NOTE AND INSTRUMENT NUMBERS? Search for "play note" and "instrument" on the Wiki. For notes, it's on the page. For instruments, there's an external link at the bottom. Alternatively, just use "See inside" and look at the dropdowns on the note and instrument blocks.
This could be used to (with a lot of typing) import sheet music into scratch. If you don't want to use the interface, you can make 3 .txt files (one with note, one with instrument, and one with beats) and import those. Then just use the play music block as ususal.