Background on Wikipedia and Old Town School of Folk Music websites ... and a thorough discussion of Skewbald the horse and several sets of the ballad lyrics - both British and American - on the Thoroughbred Heritage website.
Memphis Slim & Willie Dixon -
Leadbelly - in a call-and-response style
Lehto and Wright, a Jethro Tull-ish sounding folk rock band of Minneapolis, sing the British version
Memphis Slim's and Willie Dixon's version - lyrics and music (in D!) available in Digital Tradition collection
Also: baby-boomer folk revival versions by