I agree. Reminds me of that story about chess grandmasters having incredible memory for valid chess positions but performing no better than average when remembering random piece arrangements. There's likely some efficient compression you can achieve by playing real-world music patterns rather than random notes. And it sounds better!

An interesting middle ground might be using LLMs to generate plausible melodies based on real-world music patterns and emphasizing the unfamiliar patterns, but if the goal is to play real music fluently, nothing beats practicing with actual pieces from the repertoire you want to play.