The former Dawson's Creek star served as a presenter at the Nashville, Tennessee prizegiving, and attended a star-studded post-show bash, which featured stars including CMT Award winners Shelton and Lady Antebellum's Charles Kelley.
Van Der Beek has told People magazine the tame party soon became a raucous night of karaoke, and Shelton even used his skills as a mentor on The Voice to help coach the actor as performed.
He reveals, "I was handing off a drink, a song came on that I'd never heard before and a microphone was handed to me. Then Blake Shelton was coaching me through it note by note and I was on a table!"
Van Der Beek even posted a video of Kelley singing Michael MCDonald's What a Fool Believes on Instagram, and adds that the Need You Now hitmaker showed off his rap skills by performing Montell Jordan's 1995 track This Is How We Do It with ease.
He says, "He was amazing! When country stars karaoke, they don't sing country. I'm always going to party with country stars from here on out. They're the most fun!"