Ryan Seacrest, the Backstreet Boys, Darius Rucker and Paula Abdul have been booked to appear on the 2-hour broadcast of America\'s traditional MDA telethon. The Muscular Dystrophy Association said Tuesday the lineup for its 48th annual telethon will also feature appearances by \"Glee\" star Matthew Morrison, recording artists Luke Bryan, Lee Ann Womack and Enrique Iglesias, teenage pop sensation Austin Mahone, hip-hop dance crew Jabbawockeez, \"American Idol\" runner-up Jessica Sanchez, singer Kenny Loggins with the Blue Sky Riders, American blues rock band Vintage Trouble, and \"The Voice\" contestant Chris Mann. \"MDA Show of Strength\" is to air Sept 1 on ABC. \"The MDA telethon is an American tradition, powered by celebrities, national sponsors and, most of all, generous individuals who watch and donate,\" MDA President and Chief Executive Officer Steven M. Derks said in a statement. \"This year, we\'ll tell a powerful story of the progress we\'re making and breaking developments under way in the fight against muscle disease. We want to share our vision of hope that new lifesaving treatments are on the horizon as told through the eyes of courageous people fighting various neuromuscular diseases. \"On behalf of the tens of thousands of families we serve, MDA is remarkably hopeful and enormously grateful to all our supporters who make this progress possible. We think this year\'s show will be our best ever, truly a moving and entertaining 2-hour experience.\"