'The Voice' judges performed together in tribute to former contestant Christina Grimmie

The next season of NBC's reality singing competition The Voice doesn't begin until September 19, but in a special preview episode that aired Sunday night after the Olympics, viewers got a taste of what this season will look like — and got to see all four judges unite for a powerful tribute to former Voice contestant Christina Grimmie.

Grimmie made it to the final three on the sixth season of The Voice. In June, the 22-year-old was shot and killed while singing autographs after a show in Orlando. 

On Sunday night's special episode, the four judges, including newcomers Alicia Keys and Miley Cyrus, performed a cover of Aerosmith's "Dream On," which was dedicated to Grimmie's memory, Rolling Stone reports.

See the whole powerhouse performance below: