Putting together sounds from different melodies but arranged in a different way is a resource used often by musicians. One of the most popular and recent examples of this could be Love, an album with music of the Beatles which mixes sounds from their songs.
The fun about Mashroom is that you can mix together songs from completely different genres to create whole new sounds. It is also a great platform for sharing your creativity with other people with the same interests, because you can upload your own sounds, use them to create new tracks or simply share them so so that others can use them in their creations.
Beware that sounds with copyrights can not be used nor uploaded, so you will have some kind of limit about that. However, the amount of available sounds will be enough for you to get much time of enjoyment.
Signing up is required to use this free service, but you can do it with your Facebook acount. Just visit the site and find out about all its features if you are a music lover.
Mashroom.fm In Their Own Words
On the mashroom, you can mash up and create brand new tracks from any kind of videos from Youtube.com.
Some Questions About Mashroom.fm
The text in the site seems rather sloppy. Are they planning to write a better one? 
