This weekend on The iHeartRadio Countdown with Mario Lopez the very talented Darren Criss stops by! Darren just joined the 2019 iHeartRadio Music Festival line up and will be taking the stage with Steve Aoki! Darren and Steve just dropped a new song together, a cover song of a Dave Matthews Band Classic 'Crash Into Me' which you can check out below. So we'll catch up with him, play some throwback classics, countdown the top 20 of course and much more! Tune in!