Musician of the Year: Taylor Swift

Who: Taylor Swift, 25, musician

Why: With the deliberate embrace of a new city (New York) and a new sound (unapologetic pop), Swift conquered music mainstream this year.

If Taylor Swift wasn't the world's biggest pop star at the beginning of 2014, she certainly was by the end.

In 2014, she wrapped her $150-million The RED Tour with shows in Europe and Asia. In the summer, she had a few scene-stealing seconds in The Giver. She also moved from Nashville to New York, foreshadowing a musical shift that was in the works.

When she introduced her single Shake It Off — from the top of the Empire State Building, no less — she announced that her fifth album, 1989, would mark a full-fledged shift into the pop-music scene. But she had learned her lessons from her time in country music, staying in close touch with her fan base by poring over their Tumblr and Instagram accounts, often posting lengthy comments and even inviting a few of them to her homes to listen to the album early.

When she released her transformative 1989 album in October, she sold 1.29 million copies in the first week, outpacing any "expert" predictions and giving her the year's first million-selling release. When she released 1989's second single, Blank Space, she became the first woman to replace herself at the No. 1 spot on Billboard's Hot 100 single chart. By the end of the year, the best-selling digital musical artist ever was outselling any other album released in 2014 by at least a factor of three.

Oh, yeah, and she just turned 25.