I was recently asked how they differ. Pandora is Internet radio. It's amazing at taking the haystack of music and throwing the needle (song) out that is appropriate and joyful to your listening experience. It's a lean forward experience with rich information about songs that are playing but somewhat passive in nature in that it brings the music to you versus actively having to hunt for it.
SoundHound is the inverse. It's mobile music search, possessing the ability to reach into the haystack to tell you what the needle (song) is. Use it any time you want to conduct a music search for songs, bands, or lyrics. Then indulge in detailed, browsable results including listening and watching. In addition to text search, it enables use of the mic as a search input: voice (say it), singing and listening to the music. You can even launch a Pandora station from a search result.
