Mark Metcalfe/Getty Images

Taylor Swift Reveals Her 1989 Tour Secrets, Talks Writing 'Something Great'

'Right now, quality is the only thing I have to focus on,' Taylor said.

Didn't get a chance to see Taylor Swift's 1989 World Tour? Well, there is good news because Taylor is releasing a live concert special exclusively on Apple Music.

Apple Music, which you may remember Taylor criticized for not paying artists during its free trial launch (which they later went back on), will begin streaming the concert, "The 1989 World Tour LIVE," which was directed by Jonas Aukerland, on December 20. The show filmed in front of 76,000 fans at the ANZ Stadium in Sydney, Australia, on November 28.

Not only will the concert feature every heart pounding moment, every catchy song and Taylor's many hair flips, it will also feature some of Taylor's famous friends -- Selena Gomez, Justin Timberlake, Fetty Wap, Mick Jagger -- who helped her out on tour.

In an interview with Beats 1 Radio's Zane Lowe, Taylor revealed that she has all of her fans to thank for wanting to bring these artists out on stage.

"In this generation, I know as I'm walking on stage that a huge percentage of the crowd have already YouTubed the entire show and watched the whole thing online. They know the set list, they know the costumes, they've looked it up," she said. "That presented me with an interesting issue. I love the element of surprise...so going into this tour, having people pop on stage that you didn't expect to see -- not only musicians, but actors and athletes and models and people in every type of field."

So how did she pull it off? In many different ways, from calling up labels to texting her friends to using her dad's inside information.

"I hadn't met Fetty Wap before, so I love him and I said, 'Here are the dates we have, please come out,' and then I'd meet the artist when we got to soundcheck, and we'd get to hang out and spend time together then. And then people like my friend Selena and Lorde, I'd just text them," she said. "My dad knows everything about everyone going on in Nashville. He calls me up and goes, 'My friend was at lunch in Nashville and he swears he saw Mick Jagger,' and so I had no idea he would be in town. So I texted Mick. I said, 'Hey are you in Nashville? Do you want to come out and sing?' and he writes back, 'Oh, what will I wear?' That was the day before."

While Taylor and her fellow artists mostly have a day or two to prep for the show, she revealed that other onstage surprises happened literally hours before the concert.

"My friend Chrissy [Teigen] texted me and said, 'Hey, we are on our way to the Staples Center show,' and she's married to John Legend, and I was like, 'Is John coming with you?'," she said. "And I was like, 'Will you sing "All Of Me?"'"

Of course, John took the stage and gave the band only 35 minutes to learn his song and perfect it.

"This was very collaborative and fun and, 'Hey you want to come out? Cool. And we'll learn your song,'" Taylor said. "I have so many memories looking back and I'm going to hold onto them for dear life."

Taylor has officially wrapped her 1989 World Tour and now will enjoy some much-needed time off, but don't worry: She's still writing "something great."

"Hopefully you write with something in mind. The intent is to make something good. Don't finish a song unless it's great. I don't write 30 songs a month, I write something and when it's great, I finish it. If it's not, I'll stop halfway though and wait for something great to come along," she said before later adding, "Right now, quality is the only thing I have to focus on, make something great."