John William "Long John" Baldry was an English and Canadian blues singer and a voice actor. He sang with many British musicians, with Rod Stewart and Elton John appearing in bands led by Baldry in the 1960s. Wikipedia
Thanks for posting this. I knew his name but wasn't familiar with his work. I've begun listening to some of his stuff...he's great. I especially like "Don't Try to Lay No Boogie-Woogie on the King of Rock and Roll."