Fifteen-year-old phenom Adam Swanson (YouTube's "adamrag") challenged Frederick Hodges to play Maple Leaf Rag in B major -- an extremely difficult key in which to play it. Hodges countered with this arrangement containing multiple key changes.
Here, both of them play it in that multiple-key arrangement.
Of course, Maple Leaf Rag was composed by Scott Joplin, and published in 1899.
At the end of the video, as I pan across the audience, you can see fellow YouTuber "wilscool" standing against the wall (a few feet from Janet Klein) behind a camera tripod, so it seems he may have gotten this performance from Frederick's side of the room. Keep an eye out in case he posts that angle!
This was recorded on Saturday, 17 November 2007 at the 21st annual West Coast Ragtime Festival in Sacramento, California.
As for playing the Maple Leaf Rag in B major, Tom Brier answered that challenge at the post-festival party, playing it in a duet with Swanson. Another fellow YouTuber, tdub1941, recorded that performance, so keep an eye out for that as well.