A new PSA for St. Jude Children’s Research Hospital has some of Hollywood’s hottest A-listers singing for a good cause. Their tune of choice? None other than the Beatles’ 1968 hit "Hey Jude."In an attempt to help “make it better” for kids with cancer, Jennifer Aniston, Jon Hamm, Usher and Malin Akerman are just a few of the charitable celebs who appear in the new viral video.Along with the stars in the "Hey St. Jude" PSA, real-life patients and doctors also showcase their sweet vocals in the endearing clip.The hospital's website urges others to help by explaining, "For as little as $5, you can help us save lives. Or, donate $35 and get the #heystjude T-shirt seen in the video on our kids and your favorite celebrities."