Not to be confused with Flower Piano, the event that happens annually in July at the Botanical Garden in Golden Gate Park, PianFrancisco is a similar sort of public music effort that was started by a different guy six years ago.

Back then, Karl Reichstetter and some friends hauled a piano up to the top of Bernal Hill, and as he tells NBC Bay Area, it was just an experiment with his sister's piano. (His sister was living just about 200 feet from Bernal Heights Park at the time.)

He may have taken some inspiration from Mauro Ffortissimo, the guy behind Flower Piano, who first installed an upright piano on a bluff in Half Moon Bay in February 2013, four months before the Bernal piano appeared.

Reichstetter has been randomly installing pianos in parks ever since, having launched the effort as PianFrancisco, and latest is inside the brick building at Fort Point, beneath the Golden Gate Bridge. It's an echo-y space, and apparently the fog makes the piano keys stick, but people have been sitting down to play, and others have been stopping to listen, since the first piano landed there two weeks ago. Now, this weekend, there will be three pianos at Fort Point — and this is all in partnership with the Golden Gate National Recreation Area's "Art in the Parks" program.

If you missed this year's Flower Piano and were sad about that, or if you'll be around the Golden Gate this weekend, go check it out. The Fort Point complex is open from 10 a.m. to 5 p.m.