Nahre Sol's Practice Notes channel is a whirlwind tour of music history, with variations of well-known melodies in the styles of different composers, mashups of genres, and other delights.
What's especially great is that each stylistic element that distinguishes composers gets labeled. It's a terrific crash course or refresher of terminology.
Bonus: A Chopin nocturne turned into jazz:
The offer video lessons, too!
• Improvising in the style of different classical composers (YouTube / Practice Notes)