Christian Borngraeber has launched this brilliant project...
He is asking for help to record single notes from a huge number of pianos, and will combine them into a single virtual instrument made up of all the little piano notes.
What will it sound like? Well, we don't know yet but probably a bit like a piano.
You can email contributions in to his website, so go and grab a microphone, pick your favourite note, and record away. And there's a free party pack for everyone who helps.
Here's how you can get involved.