Sergei Stadler and the St. Petersburg Symphony Orchestra have applied for recognition in the Guinness World Records for performing all of Beethoven’s symphonies in a single day. They are not the first.
I distinctly remember Lorin Maazel pulling off the same feat in London in December 1988 as a charity stunt. He switched shoes for trainers before hitting the Ninth.
And here’s another full set in a day by Martin Brabbins.
Nothing new under the sun.