Calvin Harris believes his girlfriend Taylor Swift has "changed the entire music industry".

The singer ultimately forced upcoming streaming service Apple Music into paying out royalties on songs listened to during free trials.

The U-turn followed an open letter published by Swift on Tumblr about the value of music.

Harris, who has been dating the US star for a number of weeks, took to Instagram to pay tribute to the '1989' star's determination.

He said after a gig in Las Vegas: "I just played a gig inside a giant owl and my girl just changed the entire music industry what a day."

Apple Music meanwhile is due to launch on June 30.

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