Only releases from EMI that are over 12 months old will be available to the service's users, as part of the deal that was announced today (Thursday).
Beatles' tracks are not, however, part of the deal and will remain exclusively on iTunes for the foreseeable future.
Initially launched as an independent-only service, eMusic has steadily signed deals with major labels, starting with Sony in Q3 2009. A deal with Warner Music followed in January 2010 while Universal signed up in October 2010.
All of this major label content is currently only available to eMusic users in the US.
EMI EVP of global business development Mark Piibe said, "We're excited to be able to bring eMusic members more of the music that they love. We look forward to working with eMusic and giving our artists another way to connect with their fans and to find new audiences."
eMusic CEO and president Adam Klein added, "We are thrilled to further expand our music catalogue and give members the ability to discover and own more music through our service. We recognise that we need to expand upon the music that we offer to better cater to the varied tastes of our membership base. In adding more music to our catalogue, we will always honor our independent roots."
In November last year, a number of independent labels - notably Beggars Group and Domino - pulled their content from eMusic.