One of the biggest stories in hip-hop right now is set to play out in a courtroom later this year, when Atlanta rapper Young Thug goes on trial for gang-related activities. One of the key pieces of evidence cited in the indictment are his lyrics. The phenomenon of rap songs being played in court dates back to the early ’90s, with an early example happening in the Bay Area during the trial of one of the region’s most famous rappers, Vallejo’s own Mac Dre. There’s a lot of lore around Mac Dre’s trial, so as part of That’s My Word, KQED’s yearlong project on Bay Area hip-hop history, reporter Jessica Kariisa set out to discover what really happened. Plus, there’s all kinds of slang that comes out of hip hop, but that doesn’t mean we’re always using it the right way. Pendarvis Harshaw, host of the KQED podcast Rightnowish, has some opinions about how to use “slap.”