Around this time, mainstream rappers began to associate themselves with the hardcore scene. Playboi Carti included a performance from a hardcore show as the front cover for his 2018 album Die Lit, Denzel Curry collaborated with Bad Brains and Fucked Up in 2019 and rap groups Suicideboys and City Morgue were joined on tour by hardcore bands Turnstile and Trash Talk. Rappers Wicca Phase Springs Eternal and Ghostemane even began playing music by performing in hardcore bands. In September 2019, rap group Injury Reserve released a collaborative track with Code Orange and JPEGMafia. In 2019, the highly influential 2000's Boston hardcore band Have Heart reunited for performances in four different locations after a ten-year breakup. One of these performances was outside the Worcester Palladium in Massachusetts, which drew around 10,000 attendees, making it the largest standalone hardcore show in history. 2020s The 2020 COVID-19 pandemic has made the prospect of playing live music difficult. This has brought about a heavy digital shift in independent music, where many bands have begun performing live-stream shows for fans until physical shows can occur. With social distancing limiting the availability of physical interactions, the hardcore community has relied on social media activity, podcasting, zines, and video content to stay connected virtually. During this period, hardcore groups Chubby and the Gang and the Armed gained mainstream attention. Influence Hardcore punk has spawned a number of subgenres, fusion genres and derivative forms. Key derivatives like , emo, and skate punk have had a major impact on alternative music. Other subgenres include D-beat, melodic hardcore, crust punk, and thrashcore. Fusion genres include crossover thrash, grindcore, and metalcore, all of which fuse hardcore punk with extreme metal. Metallica and Slayer, pioneers of the heavy metal subgenre thrash metal, were influenced by a number of hardcore bands. Metallica's cover album Garage Inc. included covers of two Discharge and three Misfits songs, while Slayer's cover album Undisputed Attitude consisted of covers of predominately hardcore punk bands. The Washington state band Melvins, aside from their influence on grunge, helped create what would be known as sludge metal, which is also a combination between Black Sabbath-style music and hardcore punk. This genre developed during the early 1990s, in the Southern United States (particularly in the New Orleans metal scene). Some of the pioneering bands of sludge metal were: Eyehategod, Crowbar, Down, Buzzov*en, Acid Bath and Corrosion of Conformity. Later, bands such as