If you're looking for something other than Instant Singer, Kits is another good option. The AI audio tool suite includes voice cloning, AI singing generators, vocal remover and audio mastering. It's got a free tier and three paid tiers, so you can use it depending on how much production you're doing. It's designed to be easy to use and fair to artists, which means they get paid for their work.
Another good choice is Musicfy. This AI music generation tool lets you create music with different voices without having to know much about music. Musicfy has features like AI voice artists, custom voice creation, AI text-to-music conversion and more. It's got an easy-to-use interface and several subscription tiers, so it's good for beginners and pros.