On the day of her birthday today (Sept. 4), Beyonce surprised fans by releasing the Fifty Shades of Grey remix of her 2003 hit, "Crazy in Love," on Spotify and iTunes. Previously, the track was not available on any streaming music services, and was available only by purchasing the movie's full soundtrack album, according to Billboard.

The slowed-down version of "Crazy in Love" was first featured in the movie's teaser trailer in the summer of 2014, and was used heavily during the marketing in the months leading to the film's release on February 13, 2015.

It was revealed last year that Boots served as the producer on the updated "Crazy in Love" mix, and also worked with violinist Margot on the orchestral arrangements.

Fifty Shades of Grey, which was based on E.L. James' controversial erotic novel of the same name, opened to mostly negative reviews. But the movie's soundtrack ended up winning more people over, as it featured such hit singles as Ellie Goulding's "Love Me Like You Do" and The Weeknd's "Earned It." Billboard reported that the album sold more than 258,000 copies during its first week of release.

Click on the link below to listen to "Crazy in Love" and add it to your own personal Spotify playlists.

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