Piano rocker Elton John, folk-rocker James Taylor and country siren k.d. lang are among the artists scheduled to appear at a New York City tribute to legendary singer/songwriter Joni Mitchell. The TNT Network's "An All Star Tribute to Joni Mitchell" will take place April 6 at the Hammerstein Ballroom, according to Mitchell's publicist. It is scheduled to air on the network April 16 at 9 p.m. EST/PST. Folk-pop singer Shawn Colvin, country singer Wynonna and jazz artists Diana Krall and Cassandra Wilson also will appear. Wynonna's sister, actress Ashley Judd, will host the show. Mitchell's jazz-pop standards collection, Both Sides Now, is due Tuesday (March 21).