Styles, 18, a member of band One Direction, sent the song What makes you beautiful, sung in a country and western Style for Swift, 23.
"Even though they were apart on Christmas Day, he wanted to make sure she’d be thinking of him. The singagram was an ideal present," thesun.co.uk quoted a source as saying.
“She has a great sense of humour. He knew she’d think it was hilarious," the source added.