For a small window of time, there was an alternative... https://creolabs.com/ but this is gone now. - Source: Hacker News / 5 months ago

Alright, let's. Comparatively with what AI has already shown it can do, writing a song is not necessarily a computationally intensive task. It's just a matter of quality. Imagining that songwriting models with weights of that quality are widespread enough (i.e. There exists no monopoly), you have a situation where AI churns out music, and music of the best quality per your assumptions, in an extremely speedy way.... Source: about 1 year ago

You can use emastered.com - it will give you 320kbit MP3 without any registration. It masters beats very well. Download using curl, address is web developer console -> network. Source: over 1 year ago

I'd drag it on here and see what you think. It'll take you < 5 minutes and $0 to try it. If you like the result, it could save you a lot of headaches. Source: almost 3 years ago

You can also try emastered.com. Worse than a pro master, but better than you can do yourself probably. You can try it for free, and it's not expensive if you'll master multiple songs. Source: about 3 years ago