Ella Jenkins, First Lady of Children's Music, who's been recording music for kids for 50 years, has sadly been virtually absent from music downloading.
Until now. You can now get, oh, about 500 Ella Jenkins songs at the Smithsonian's Global Sound website. And the songs will soon make their way to other music download sites (such as familiar ones starting with the letter "i" or "e").
And while you're tooling around that website, make sure you check out this page and the "Children's Music" program (#16). It's a quality, 54-minute introduction to Smithsonian Folkways' kids' collection -- it includes not only the classics (Ella -- with an interview to boot, Woody, Lead Belly, Pete) but some other unfamiliar stuff, like an awesome "Brown Girl in the Ring" by Lord Invader and the Calypso Orchestra about 22 minutes in. Worth checking out if you've got the time.