In October, Bad Boy Records’ Machine Gun Kelly topped the Billboard 200 for the first time with his fifth album, Tickets To My Downfall – charting higher with guitar-driven pop-punk songs than he ever had as an emcee. Two weeks later, the top spot on the Hot 100 was secured by “Mood,” a guitar-driven emo-rap song by 24kGoldn and Iann Dior, who have since ruled the chart for most of the last two months. But those feel like only the most prominent tipping points of an unlikely alliance between pop-punk and hip-hop — one that has been everywhere in 2020, bubbling up in recent years to finally reach the forefront of popular music. Once upon a time, hip-hop and punk bubbled out of New York City as parallel movements that intersected often, from Debbie Harry rhyming about Fab Five Fre...