The 49th broadcast of the television fundraising event will continue through 11 PM.

The evening will feature performances by Rascal Flatts, LeAnn Rimes, Aloe Blacc, American Authors, Bret Michaels, Fall Out Boy, Jason Derulo, Matt Nathanson, R5 and Sara Evans.

Celebrity presenters include Alyssa Milano, Brad Paisley, Charles Esten, Chris Powell, Jann Carl, Jordin Sparks, Josh Groban, Kesha, Kevin Frazier, Laila Ali, Ludacris, Nancy O’Dell, Pete Wentz, ABC’s Dr. Richard Besser, Susan Lucci, Terry Fator, Tom Bergeron and Victor Ortiz.

“MDA’s telethon gives us a chance to celebrate the compassionate support of our celebrity friends, sponsors and individuals in communities across the country who give generously to help save and improve lives of those fighting muscle disease,” said MDA president and CEO Steven M. Derks in a statement. "With clinical trials of potential new therapies underway, this is a time of hope and progress for the children and adults we serve. We urge families and friends to gather together on Aug. 31 to watch, whether via broadcast or online, and see the fantastic performers and inspiring stories of those who are fighting muscle disease with grace and courage."

The broadcast will also spotlight five families who will share their stories and give the public a glimpse of what it means to live with a muscle disease. The complete list of family profiles includes:

• JoeJoe and Dominik Stoop, two energetic brothers, ages 5 and 3, respectively, from Los Angeles who are living with spinal muscular atrophy (SMA)
• Torrance Johnson, an outgoing and charismatic 8-year-old from Canton, MI, also affected by SMA
• 13-year-old football fanatic Kasey Bennett of Houston who has Duchenne muscular dystrophy (DMD)
• Kate Pecora, 15, a mature young lady from North Reading, MA, living with SMA and taking part in a promising new clinical trial
• Eric Von Schaumburg, 31, from Chicago, who is battling amyotrophic lateral sclerosis (ALS) with a “take no prisoners” attitude, and help from his loving family and girlfriend Lindsay.

The Muscular Dystrophy Association is the world’s leading nonprofit health agency dedicated to saving and improving the lives of anyone with muscle disease, including muscular dystrophy, amyotrophic lateral sclerosis (ALS) and other neuromuscular diseases. Visit mda.org.