After starting out as a free Android application, last year saw Shazam switch to a lite and paid apps model. SoundHound, on the other hand, has taken the opposite route.  Last week, the company announced that users can now enjoy unlimited access to music recognition.  Using ad subsidy, the app provides access to lyrics, artist search, and previews to today’s top songs.  Read more details about the application at SoundHound’s website.  Users can opt out of the ads with a one-time $4.99 purchase.