I produce games written in NextBASIC for the ZX Spectrum Next, and music for the ZX Spectrum Next, (using Gari Biasillo's NextDAW software.) - Music Playilst on YouTube
I am also able to provide music for other people's game projects on the Next. If you're able to use NextDAW's .NDR files in your code and you need music for your project, send me a message to discuss possibilities.
Everything available for the ZX Spectrum Next on itch.io