Post Malone becomes one of the 10 artists with the most No. 1s on Billboard’s Rhythmic Airplay chart as “Cooped Up,” featuring Roddy Ricch, tops the list dated July 30. The single advances from No. 2 after it gained 4% in plays to become the most-played song at U.S. monitored rhythmic radio stations in the week ending July 24, according to Luminate. “Cooped,” released on Mercury/Republic Records, gives Post Malone his ninth champ on Rhythmic Airplay. Here’s a recap of his leaders: “White Iverson,” one week at No. 1, beginning Jan. 2, 2016“Rockstar,” featuring 21 Savage, six, Nov. 11, 2017“Psycho,” featuring Ty Dolla $ign, four, April 28, 2018“Sunflower (Spider-Man: Into the Spider-Verse),” four, Jan. 19, 2019“Wow.,” five, Feb. 23, 2019“Goodbyes,” featuring Young Thug, one, Sept. 21, 2019“E...