Taylor Swift's 1989 Tour: See All of Her Special Guests!

Taylor Swift and Allesia Cara perform "Here" on Taylor Swift's "The 1989 World Tour" at Raymond James Stadium on Oct. 31, 2015 in Tampa, Fl. Read the story.

When it comes to music, there's no objective right or wrong, good or bad – but that never stops passionate music fans from sharing and defending their favorites. From pop hooks to album covers to beats, we're rounding up some of the greatest of all time in music on Billboard. We spent months discussing, researching and reflecting on music from artists old and new, considering everything from sales to impact to innovation to longevity. The results won't please everyone – and that's as it should be. Everyone has their own takes on the greatest in music – this is ours.
Check it out.

Taylor Swift and Ricky Martin at American Airlines Arena on October 27, 2015 in Miami, Florida.

Taylor Swift and Pitbull at American Airlines Arena on October 27, 2015 in Miami, Florida.

Taylor Swift and Dwyane Wade at American Airlines Arena on October 27, 2015 in Miami, Florida.

Taylor Swift and Tove Lo on stage at The 1989 World Tour at the Georgia Dome on Oct. 24, 2015 in Atlanta, Georgia. Read the story.

Taylor Swift and Miranda Lambert performs during the 1989 World Tour at the Greensboro Coliseum on October 21, 2015 in Greensboro, North Carolina. Read the story.

Ellie Goulding and Taylor Swift perform onstage during the 1989 World Tour Live on Oct. 17, 2015 at the AT&T Stadium in Arlington, Texas. Read the story.

Charli XCX joins Taylor Swift to perform during The 1989 World Tour at Rogers Center on October 3, 2015 in Toronto, Canada. Read the story.

Taylor Swift and Keith Urban perform during The 1989 World Tour live in Toronto at Rogers Center on October 2, 2015 in Toronto, Canada.Read the story.

Taylor Swift performs with special guest Nelly onstage during the 1989 World Tour at Scottrade Center on September 29, 2015 in St Louis, Missouri. Read the story.

Taylor Swift and Steven Tyler perform onstage during The 1989 World Tour live in Nashville at Bridgestone Arena on Sept. 25, 2015 in Nashville, Tennessee. Read the story.

Taylor Swift and Leona Lewis perform during The 1989 World Tour live in Nashville at Bridgestone Arena at Bridgestone Arena on September 26, 2015 in Nashville, Tennessee. Read the story.

Kelsea Ballerini and Taylor Swift perform during The 1989 World Tour live in Nashville at Bridgestone Arena on September 25, 2015 in Nashville, Tennessee. Read the story.

Taylor Swift and Mick Jagger perform onstage during The 1989 World Tour live in Nashville at Bridgestone Arena at Bridgestone Arena on Sept. 26, 2015 in Nashville, Tennessee. Read the story.

Taylor Swift and Alison Krauss perform during The 1989 World Tour live in Nashville at Bridgestone Arena on September 25, 2015 in Nashville, Tennessee. Read the story.

Taylor Swift and Dierks Bentley perform onstage at the Sprint Center on September 21, 2015 in Kansas City, Missouri.

Sydney Sierota and Taylor Swift perform during The 1989 World Tour at Nationwide Arena on Sept. 18, 2015 in Columbus, Ohio.Read the story.

Taylor Swift and The Band Perry perform "If I Die Young" at Bankers Life Fieldhouse on Sept. 16, 2015 in Indianapolis. Read the story.

Taylor Swift with special guest Wiz Khalifa during the Taylor Swift The 1989 World Tour Live In Houston at Minute Maid Park on September 9, 2015 in Houston, Texas.

Taylor Swift and Omi perform during Taylor Swift The 1989 World Tour Live In San Diego at PETCO Park on August 29, 2015 in San Diego, California. Read the story.

Taylor Swift and Avril Lavigne onstage during Taylor Swift The 1989 World Tour Live In San Diego at PETCO Park on August 29, 2015 in San Diego, California. Read the story.

Taylor Swift and Selena Gomez perform during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 26, 2015 in Los Angeles, California. Read the story.

Justin Timberlake and Taylor Swift perform onstage during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on Aug. 26, 2015 in Los Angeles, California. Read the story.

Taylor Swift and Phoebe Buffay (Lisa Kudrow) sing "Smelly Cat" onstage during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 26, 2015 in Los Angeles. Read the story.

Beck, Taylor Swift and St. Vincent perform during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 25, 2015 in Los Angeles, California. Read the story.

John Legend and Taylor Swift perform "All of Me" onstage during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 25, 2015 in Los Angeles. Read the story.

Alanis Morissette joins Taylor Swift onstage during The 1989 World Tour Live In Los Angeles at Staples Center on August 24, 2015 in Los Angeles. Read the story.

Taylor Swift and Natalie Maines of Dixie Chicks perform onstage during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 24, 2015 in Los Angeles. Read the story.

Taylor Swift and Ellen DeGeneres perform during Taylor Swifts The 1989 World Tour Live In Los Angeles at Staples Center on August 24, 2015 in Los Angeles, California. Read the story.

Matt Leblanc, Taylor Swift, Chris Rock and Sean O'Pry perform during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 22, 2015 in Los Angeles, California.

Uzo Aduba and Taylor Swift perform during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 22, 2015 in Los Angeles, California.

Taylor Swift and Mary J. Blige perform during Taylor Swift The 1989 World Tour Live In Los Angeles at Staples Center on August 22, 2015 in Los Angeles, California.

Taylor Swift, Joan Beaz and Julia Roberts take a bow on stage during Swift's "The 1989 World Tour" at Levi's Stadium on August 15, 2015 in Santa Clara, California. Read the story.

Taylor Swift and Little Mix perform together during Swift's "The 1989 World Tour" at Levi's Stadium on Aug. 15, 2015 in Santa Clara, California. Read the story.

Taylor Swift, Dina Jane Hansen, Normani Kordei, Camila Corbello, Ally Brooke and Lauren Jauregi of Fifth Harmony perform at Levi's Stadium on August 14, 2015 in Santa Clara, California.Read the story.

Taylor Swift and Fetty Wap at CenturyLink Field on Aug. 8, 2015 in Seattle, Washington. Read the story.

Taylor Swift and Shawn Mendes at CenturyLink Field on August 8, 2015 in Seattle, Washington.

Taylor Swift, Russell Wilson and Ciara perform at CenturyLink Field on August 8, 2015 in Seattle, Washington.

Taylor Swift performs "Am I Wrong" with special guests Nico and Vinz during The 1989 World Tour Live at BC Place Stadium August 1, 2015 in Vancouver, British Columbia, Canada. Read the story.

Taylor Swift performs with Malcolm Kelly and Tony Oller of MKTO at Gillette Stadium on July 25, 2015 in Foxboro, Massachusetts. Read the story.

Taylor Swift and Nicholas Petricca of Walk the Moon perform at Gillette Stadium on July 24, 2015 in Foxboro, Massachusetts.

Taylor Swift and Sam Hunt perform during The 1989 Tour at Soldier Field on July 19, 2015 in Chicago, Illinois. Read the story.

Taylor Swift performs with Andreja Pejic and Lily Donaldson during The 1989 World Tour at Soldier Field on July 19, 2015 in Chicago. Read the story.

Taylor Swift and Serayah McNeill perform during The 1989 World Tour at Soldier Field on July 18, 2015 in Chicago. Read the story.

Andy Grammer and Taylor Swift perform during The 1989 Tour at Soldier Field on July 18, 2015 in Chicago, Illinois. Read the story.

Taylor Swift and Jason Derulo perform onstage during The 1989 World Tour Live at Nationals Park on July 14, 2015 in Washington, DC. Read the story.

Taylor Swift and Lorde perform onstage during The 1989 World Tour Live at Nationals Park on July 13, 2015 in Washington DC. Read the story.

Nick Jonas and Taylor Swift perform during The 1989 World Tour Live at MetLife Stadium on July 11, 2015 in East Rutherford, New Jersey. Read the story.

Taylor Swift performs with Hailee Steinfeld, Gigi Hadid, Lily Aldridge and Lena Dunham during The 1989 World Tour Live at MetLife Stadium on July 10, 2015 in East Rutherford, New Jersey. Read the story

World Cup Champions U.S. Women's Soccer National Team, Heidi Klum and Taylor Swift onstage during The 1989 World Tour Live at MetLife Stadium on July 10, 2015 in East Rutherford, New Jersey. Read the story

Alana Haim, Danielle Haim and Este Haim of the band Haim perform during Taylor Swift's The 1989 World Tour Live at MetLife Stadium on July 10, 2015 in East Rutherford, New Jersey.

Taylor Swift performs with The Weeknd during The 1989 World Tour Live at MetLife Stadium on July 10, 2015 in East Rutherford, New Jersey. Read the story

Martha Hunt, Kendall Jenner, Serena Williams, Taylor Swift, Karlie Kloss, Gigi Hadid and Cara Delevingne perform onstage during The 1989 World Tour at Hyde Park on June 27, 2015 in London, England. Read the story.

Ellie Goulding performs at Hyde Park on June 27, 2015 in London, England.

Taylor Swift performs onstage with musician Rachel Platten during The 1989 World Tour on June 13, 2015 at Lincoln Financial Field in Philadelphia. Read the story.

Mariska Hargitay, Taylor Swift, and Cara Delevingne pose onstage during The 1989 World Tour on June 12, 2015 at Lincoln Financial Field in Philadelphia, Pennsylvania. Read the story.

Taylor Swift performs onstage with Sydney Sierota of Echosmith during The 1989 World Tour on June 12, 2015 at Lincoln Financial Field in Philadelphia, Pennsylvania.

Taylor Swift performs with the band Little Big Town during The 1989 World Tour live at Heinz Field on June 6, 2015 in Pittsburgh, Pennsylvania. Read the story.

Taylor Swift and Dan Reynolds of Imagine Dragons perform on stage during the 1989 World Tour Live at Ford Field on May 30, 2015 in Detroit, Michigan. Read the story.