Country and Americana legend Dwight Yoakam (who's repped for live by John Huie at CAA) invited a special guest onstage during his 7/25 show at L.A.'s Greek Theatre: Post Malone, whose forthcoming Mercury/Republic country project, F-1 Trillion, is generating tremendous buzz. UTA-booked Posty seemed to prefer playing sideman than duet partner during his visit, and was clearly in awe of the headlining star. Word has it Post appears on a new cut from the Activist-managed Yoakam, which is said to be coming in a couple of weeks.