Two weeks after Amazon announced that its Cloud Player music service would be made available via several 2013 Ford vehicles equipped with SYNC AppLink, Spotify has announced a similar partnership. The streaming music service will offers its catalog of over 20 million songs via Ford vehicles, too, the firm such partnership for Spotify.

See Amazon Cloud Player Now Available in Ford SYNC-Equipped Vehicles for more details about the Amazon deal. In addition to Amazon, Spotify joins Pandora, MOG Music, Slacker, and Rhapsody on the Ford SYNC platform.

And as with Cloud Player, the Spotify integration will require Ford SYNC AppLink in the vehicles and new versions of the Spotify app for iPhone and Android, which are due soon. (I assume Windows Phone users will eventually receive this compatibility as well, but I won’t hold my breath to press the point.) It can be fully controlled via voice commands in addition to the in-dash touch controls.

One thing worth remembering is that while Spotify and Amazon Cloud Player are both broadly defined as online music services, they serve very different markets. Spotify is more akin to Pandora or even Xbox Music Pass in that it provides streaming access to the firm’s voluminous online catalog of music, and is similar to an Internet-based radio, with “stations” based on artist preferences. Amazon’s service is an online storage locker for the user’s own content, and is thus filled with previously purchased music from Amazon or other services, or music that was ripped from CD. So in many ways they’re complementary.

Speaking of complementary, Ford’s sudden surge in SYNC AppLink music services integration could soon be further bolstered by apps created with the firm’s recent release of an app development platform. Ford already has over 60 apps available for SYNC, and many more are on the way. So don’t be surprised to see an in-dash app store start appearing in these vehicles soon as well.