How hard can it be to play a one-minute piece of music on the piano — or violin, guitar, tuba, oboe, basically your instrument of choice?

Wait, what? Play it 840 times?

Well that’s a different story.

But that’s what will happen on Saturday, Dec. 2, when anywhere from two to several dozen musicians pack the patio at Hotel Congress for the first-ever “Vexations” marathon, 16 hours of non-stop performances of Erik Satie’s admittedly weird one-minute piece “Vexations.”

So far, 18 musicians have signed on for the marathon, hosted and organized by Tucson’s DIY composing project ChamberLab. Participants get sponsors to pledge a per-performance donation up to 840 performances.

The number is not random; Satie scribbled a note on top of the 1893 score instructing players to repeat the piece 840 times.

ChamberLab founder/curator Chris Black will be the anchor pianist, kind of the pseudo conductor keeping the players on script. The goal, he said, is to play Vexations non-stop from 8 a.m. to midnight Dec. 2, including when they move the action around 10 p.m. from the Congress patio to Maynards Kitchen across Toole Avenue.

“At any given time it could be just two people sitting there, just a pianist, and then all of a sudden 20 people could show up,” Black said last week, then wished aloud that at least 100 musicians would sign up. Stranger things have happened, he conceded; after all, Tucson is a notorious last-minute town.

And the Vexations marathon is for a good cause; all proceeds will benefit the ACLU. Black said he would love to raise $10,000.

In addition to the musicians, Black said he also has a group of dancers interested in participating.

“They are going to choreograph a step and repeat it over and over again,” he said.

Although Satie wrote “Vexations” for piano, Black has arranged it for just about any instrument including flute, violin, cello, bass, trumpet, clarinet, saxophone, viola, bassoon, trombone, guitar and ukelele. You can find the music at chamberlab.org/vexations

Imagine a big mix of those instruments — a couple pianists, a violinist or two, wind players, a little guitar and maybe a ukelele for a little twang — sharing the patio and playing in unison. That’s what Black is hoping for. And as far as he knows, it will be a first, not just for Tucson but ever, anywhere that someone has performed “Vexations” on instruments other than piano.

It also could be the first time the work has been cast in a marathon.

“The whole point is to raise money for the ACLU so the more musicians we have, the more sponsors we have and the more money we get to raise,” Black said.

Contact reporter Cathalena E. Burch at cburch@tucson.com or 573-4642. On Twitter @Starburch