Glee's Whitney Houston homage episode airs April 24, but in the meantime there's video of a quartet of the show's vocalists delivering a an a capella version of one of Houston's early signature hits: "How Will I Know".
Watch Mercedes (Amber Riley), Rachel (Lea Michele), Kurt (Chris Colfer), and Santana (Naya Rivera) pay tribute to Houston with one of the most affecting numbers Glee has put together in a while.






























