Taylor Swift Wins Song of the Year at 2015 iHeartRadio Music Awards

Taylor Swift won Song of the Year honors at the 2015 iHeartRadio Music Awards on Sunday night (March 29) with her massive hit, "Shake It Off."

Madonna presented the award after Swift joined her on acoustic guitar for a performance earlier in the broadcast.

The song was the lead single from Swift's first official foray into pop, 1989. It was a huge multi-format hit, inspiring a number of tribute videos from ordinary folks dancing to "THIS.SICK.BEAT."

"I want to thank Madonna for being Madonna first of all," Swift said from the stage. She went on to thank her co-writers, Max Martin and Shellback.

"It was the most fun I've ever had writing a song, and then it went out into the world, and  I got to see all these little kids and police officers and colleges and everyone making videos dancing to it," she added. "And just getting to make a song that's played at wedding receptions and parties and things like that, it makes me really happy. "

Swift also won Best Lyrics earlier in the evening for "Blank Space." She is gearing up for her 1989 world tour, which launches on May 20.

"Thank you to all the fans, who I cannot wait to see you dance to this on tour," she finished.

See 2015 iHeartRadio Music Awards Red Carpet Pictures