Musicroamer - A visual Pandora for discovering new music
Music Walker - Explore and play (via YouTube) songs similar to a seed song.
BandNext - Discover bands that sound similar to artists you already love with BandNext. A single click saves your results to a Youtube playlist.
Songstack - Swipe to discover new music for Spotify
remixmonsta - Tired of Despacito? Find a cool remix instead
The Rick Astley Remixer - Remix your favourite songs in your browser.