Musicovery is a very interesting web application which plays music online with your choice of decade, genre, mood, tempo, and so on. From rock to classical, from 50s to nowadays, there's a huge selection of music to listen to. After finishing one song, it continuously plays the next song within your choice.
Musicovery is a good way to find new songs matching your taste, even with different styles. Try unchecking the "hit" box and selecting "discovery". You may unearth many unknown bands and you might just learn to love it! So, what you waiting for? Play it!