This is the Top Five Countdown! We're detonating the five most popular songs in the Billboard Hot 100 Pop Singles chart, for the week ending Sept. 23, 2017. Sometimes the Top Five can lull you to sleep with its slowness … and then there are weeks like this. Number 5: Logic Featuring Alessia Cara & Khalid "1-800-273-8255" It all starts in fifth place, where we welcome newcomer Logic, who surges four slots to fifth place with "1-800-273-8255" featuring Alessia Cara and Khalid. What's with that song title? Logic hails from Gaithersburg, Maryland, not far from Washington, D.C. The song title is the telephone number for the National Suicide Prevention Lifeline. Logic says the inspiration for this song came on a recent tour, when he stayed in fans' homes. Logic says some told him his music helped save their lives … which showed him his power as an artist. Number 4: Taylor Swift "Ready for It?" No artist is more aware of her own power than our fourth-place newcomer. Taylor Swift is back, and she came to play with "Ready For It?" Taylor maintained a low profile for much of the past year, then last month re-emerged in a burst of activity on social media. Her sixth album "Reputation" arrives on November 10. "Ready For It?" features songwriting and production from the solid-gold team of Max Martin and Shellback. It appeared on September 3, immediately becoming Taylor's 13th number one single on the Billboard Digital Songs chart. Number 3: Luis Fonsi & Daddy Yankee Featuring Justin Bieber "Despacito" Ms. Swift isn't finished with us yet, but right now let's bring on Luis Fonsi, Daddy Yankee and Justin Bieber: "Despacito" backs off a notch to number three. On September 16, Luis gave a special private performance in San Antonio, Texas. He stopped by the Children's Rehabilitation Institute of TeleTon USA. He sang for the young patients, who battle musculoskeletal and neurological disorders. Number 2: Cari B "Bodak Yellow (Money Moves)" Cardi B gets serious this week, as "Bodak Yellow" moves into the runner-up slot. The Bronx rapper was previously on track to drop her debut album in October, but now says she may need a bit more time to finish it. Number 1: Taylor Swift "Look What You Made Me Do" November 10 is the day Taylor Swift delivers her "Reputation" album, and the lead single remains atop the Hot 100. Ruling the roost for a second week: "Look What You Made Me Do." This marks the first time in nearly three years that two solo women control the Hot 100. It last happened in December 2014: Taylor Swift was again in the driver's seat with "Blank Space," while Meghan Trainor was the runner-up with "All About That Bass." We're all about those hits, and we'll have more for you next week — so join us if you can.