This is the Top Five Countdown! We’re on the march with the five most popular songs in the Billboard Hot 100 Pop Singles chart, for the week ending Dec. 9, 2017. If you feel your week isn’t complete without a new song in the hit list, then you’ll be happy you joined us today. Number 5: Ed Sheeran "Perfect" It happens in fifth place, where Ed Sheeran jumps two slots with "Perfect." Last week, Ed dropped the remix which features Beyonce. It’s on track to become Ed’s fourth number one single in the U.K., but it didn’t come easily. Ed tells Entertainment Tonight that Beyonce changes her email address weekly, so contacting her wasn’t simple. Once they got together, however, things went smoothly: Ed says Beyonce only needed one take to nail her vocal part. Number 4: Imagine Dragons "Thunder" Imagine Dragons holds in fourth place with "Thunder." On January 6, the Las Vegas rockers kick off their world tour in Kuala Lumpur, Malaysia. Other stops on the Asian leg include Singapore, Japan, Thailand, Taiwan, Hong Kong and China. On January 17, the band will make its second appearance in Shanghai. They first performed there in August 2015. Number 3: Lil Pump "Gucci Gang" Lil Pump remains your third-place entry with "Gucci Gang." Lasting a scant two minutes and four seconds, this is the shortest Top 10 single in 42 years. Back in October 1975, Dickie Goodman hit fourth place with "Mr. Jaws," which clocked in at two minutes and three seconds. Number 2: Camila Cabello Featuring Young Thug "Havana" Also in a holding pattern this week are your second-place artists, Camila Cabello and Young Thug, with "Havana." Back in May, Camila announced that her debut solo album would be titled "The Hurting, The Healing, The Loving," and arrive this year. Camila later amended that, saying she was still working on material. This week, she went on social media to announce that the album, now titled simply "Camila," will hit the market on January 12. Number 1: Post Malone Featuring 21 Savage "Rockstar" Post Malone and 21 Savage remain your countdown champs for a seventh big week with "Rockstar." Last week, Post announced a December 1 release date for his second album, "Beerbongs & Bentleys." Well, December 1 came and went, with no album to show for it. That same day, Post went on Twitter. He apologized for the delay, saying he’s still working on making it the best album possible. As for when we get it … that’s still up in the air.