Mekhi Phiffer & Jaleel White will guest star in tomorrow's episode of Psych, the USA Network's detective dramedy series, which stars Dule Hill as Gus.

In the musical episode titled "Let's Doo-Wop It Again," Gus’ a capella group from college, which include the characters of Phifer and White, reunite to create harmonious melodies and solve an inner-city hero crime.

The episode airs tomorrow Wednesday, March 21on USA Network at 10/9c.

Check out a preview below.