Earlier this year, when Fortune Magazine ranked Taylor Swift No. 6 on its list of the "world's greatest leaders" — ahead of GM CEO Mary Barra, Facebook's Mark Zuckerberg and Bill and Melinda Gates — the haters, well, hated.

One commenter on Fortune's story said, "Fortune just lost my respect...Taylor Swift??? C'mon." On Twitter, some responded with confusion. "Fortune Magazine's definition of LEADER needs some explaining," one former CEO wrote. And to another story covering the list, a reader responded, "What exactly has Swift done for the world anyway?"

Swift answered that question with force Sunday night when she penned an open letter to Apple, criticizing the tech behemoth for its new music service, which was going to offer a free trial period to consumers during which musicians wouldn't get paid. "I find it to be shocking, disappointing, and completely unlike this historically progressive and generous company," Swift wrote.

Apple quickly changed course, and the Internet exploded in applause. Musicians thanked her. People on Twitter asked her to use her apparently magic powers to fix the crisis in Greece and pass gun control legislation. And business columnists heralded her leadership prowess, with headlines calling her an example of "open leadership" and "A C-suite role model."

Swift's ability to get the massive tech giant to switch gears wasn't the first time the pop star has been recognized for her influence, of course. Fortune has cited her brand savvy, her application to trademark some of her phrases, and her move to pull all her music from Spotify over how the streaming service pays musicians.

Time magazine, which named her as a finalist as its Person of the Year, has also highlighted her power in the industry. In a cover story, it examined Swift's thoughts about the lack of female role models in music and her ability to make the industry believe big albums can matter again.

Last summer, Swift herself wrote an insightful and optimistic op-ed in the Wall Street Journal (under the label "Journal Reports: Leadership") where she shared her hopes for other artists not undervaluing their work, her approach to her relationships with fans and her predictions on the future of music.

"Another theme I see fading into the gray is genre distinction," wrote the former Nashville star turned pop artist. "I think that in the coming decades the idea of genres will become less of a career-defining path and more of an organizational tool."

Not only does she have more than 59 million Twitter followers and a reported net worth of $200 million. she was also the nation's best-selling artist in 2008, 2010 and the second best in 2012. Her latest album, "1989," sold 3.66 million copies last year to become the best-selling album (even beating out the "Frozen" soundtrack). The first week of its release, it sold more than 1.2 million copies, better than any since 2002.

But for all that power, insight and influence — and for all those record sales — what truly makes Swift a leader in the industry is her interest in using her position to speak out on behalf of other artists.

She did so with full-throated force in her letter Sunday to Apple, when she wrote that "this is not about me. Thankfully I am on my fifth album and can support myself, my band, crew, and entire management team by playing live shows. This is about the new artist or band that has just released their first single and will not be paid for its success. This is about the young songwriter who just got his or her first cut and thought that the royalties from that would get them out of debt. This is about the producer who works tirelessly to innovate and create, just like the innovators and creators at Apple are pioneering in their field…but will not get paid for a quarter of a year’s worth of plays on his or her songs."

She went on: "These are not the complaints of a spoiled, petulant child. These are the echoed sentiments of every artist, writer and producer in my social circles who are afraid to speak up publicly because we admire and respect Apple so much."

So yes, Taylor Swift is a leader. She may not be perfect: After the Apple story broke, a photographer criticized the demands her management company has made about photo rights. And whether her leadership should rank above that of country presidents or global CEOs is a worthy question. But more and more she's been proving why she merits many of the leadership accolades she's received.

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