Here is a list that I’ve compiled containing all the music discovery tools out their on the internet. I’ve also included the clustering method, the pros, and the cons of each website.

Website Clustering Purpose Pros Cons
Every Noice at Once Genre One page full of genres organized by color and proximity, which play samples when you click on one Great site finding new genres Coloring scheme is a little disorienting
Furzr Genre Shows a visual representation of bands and their proximity, but is also interactive Interactivity helps to easily explore tree Clustering is a bit off, as bands seem to cluster together based on how new they are rather than genre/style
IndieShuffle Genre Pulls the best new SoundCloud songs Newest songs are available to stream in playlists Must choose by Genre and cannot search by artist similarity
Last.fm Genre Get artist information including top tracks, bios, and similar artists Easy to stream similar sounding artists Similar artists tend to be more popular
LivePlasma Genre Shows a tree linking to similar bands Very pretty to look at Clustering includes mostly popular bands
Music-map Genre Enter a band name to see a visual map of similar bands, with their distance approximating their similarity Shows a lot of bands in a single tree Not a huge varitey of indie bands so the same ones will show up often, no streaming.
Musicroamer Genre Generate a visual tree with top tracks for streaming Easy to get a good sample of top tracks Trees tend to be very small and lots of clicking required to generate playlists
Music Suggestions Ninja Genre Retrieve a streamable playlist of 7-10 bands based off a single band Huge database of bands containing many lesser known Solo artists and their bands often cluster together
Tubalr Mood/Genre Generates playlists based on mood to stream automatically Easy to stream and search It is user based so the mood and genres are all over the place
Spotify Artist Explorer Popularity/Genre Shows a tree based on a band or genre Can stream automatically and has nice visuals Shows mostly popular music, and does not show hard to find or new bands
Gnoosic User network Enter a favorite band name to get similar music from people that share your band as a favorite Can give good unexpected results Can also give predictable results - i.e. everyone that likes Beethoven also likes Schubert, Wagner, Chopin
TasteKiD User network Recommends similar bands from a large repertoire and gives bio and samples Good tool for learning bios and getting a sample User-based so bands have to have some popularity to appear as recommendation
What the f!$% should I listen to right now User network Enter a band name and get another one that is related Has good unexpected results Only shows one band at a time and requires clicking
RetroJam Release date Retrieve songs from any month/day/year Easy to use and unique idea Not a huge range of time and not too many bands (mostly popular)
Songza Mood Searchable playlists for any daily activity Includes many activities and curated playlists Not a huge selection of playlists and bands
StereoMood Mood Generates playlists based on mood Lots of moods available to choose from and streamble from site Playlists are short