Which algorithm innovation led to a major improvement in music recommendation accuracy on streaming platforms around 2015-2016?

The music industry has undergone massive transformation with the rise of streaming platforms. These services have revolutionized how artists distribute music, how consumers discover new tracks, and how the industry collects and analyzes listening data. This poll tests your knowledge about a significant retail data analytics breakthrough that changed how streaming platforms recommend music to listeners.

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Collaborative filtering with neural networks
Basic genre classification systems
Manual curator playlists
Simple popularity-based recommendations