Somerville based The Echo Nest, which offeres a music intelligence API that powers music apps for media companies and thousands of developers, has just announced a music app contest centered on Facebook. The best app built off from The Echo Nest’s API that integrates with Facebook will take home $10,000 in cash in winnings.

The contest aligns with a new music ID mapping service added to The Echo Nest API. The idea is to push listeners — regardless of where they are tuning in — to artists’ Facebook pages while they are listening to said artists’ tunes. Ultimately this is in hopes of that listener “Liking” the artist and continuing to connect and follow them on the social network — a place they likely frequent every day.

Called Rosetta Stone, this portion of The Echo Nest’s API acts as a “universal artist ID translator” and allows developers to map music offerings to a slew of services like MusicBrainz, Rdio, 7digital — and now Facebook. The Echo Nest’s rich music data API currently houses over 5 billion data points around 18 million songs composed by 1.5 million artists.

The contest will award The Echo Nest’s trademarked blue Sweatsedo suits (right) filled with $10,000 to the developer who builds the best app using their API and this new Facebook feature. The contest ends on August 10, 2011 and judges include Paul Lamere, The Echo Nest director of developer platform, and Eliot Van Buskirk, editor of Evolver.fm, which is published by The Echo Nest.

“Though music is probably the most social entertainment medium, truly social music applications are still in their infancy,” said Jim Lucchese, CEO of The Echo Nest. “Our goal with the launch of Rosetta for Facebook and the $10,000 Sweatsedo prize is to give developers the tools and incentive to build better music apps that incorporate what Facebook has to offer artists and their fans.”

Curious about why The Echo Nest’s API is so revolutionary? Currently there is no sole, unique identifier for artists and songs. Across the web music services and social networks list all these artists and songs, each using different identifiers and URLs to refer to the same artists, making it difficult for any developers building music apps and services. The Echo Nest constantly scours the web for new artist and music info, maps it to a universal music ID, and then offers this massive repository for developers to tap to easily build music apps. Over 160 music applications have been built using its API to date

Interested in submitting an app to the contest? You can find more information about it here.