A. “What's Poppin” is Jack’s most popular song. However, it is not the original lead track to the EP Sweet Action that made his song viral. The later remix of the song features Tory Lanez, Lil Wayne, and DaBaby, and is the version of the song that went viral on TikTok. However, with the recent release of First Class and its subsequent virality on TikTok, it can be argued that First Class has overtaken What's Poppin as Harlow’s most popular song.