This was a plugin we created to easily transfer songs made in Minecraft to an nbs file. nbs files can be opened by Minecraft Note Block Studio, and can be used by any plugin which supports Note Block API
Click above to view the demo video
https://www.spigotmc.org/resources/rodisongsaver.65499/
/record <song name> <file name>
You can surround the song or file name in quotation marks to be able to add spaces in the name. After executing this command, any note block sounds played will be recorded. Clicking the "end recording" message in chat will end the recording, and save the nbs file to plugins/RodiSongSaver.