How low is a piano?

Very interesting responses folks. Thanks! Am I correct about the low bass string? I wasn't sure.

Actually it's 41Hz in standard tuning.

Grimace - You are correct (41.2Hz). There are 5 or 6 string electric bass guitars that have additional B string (31Hz) but it is made only for ease of playing. Composers would avoid writing music for 5 or 6 string instrument exclusively where most common bass has 4 strings.

I wonder why they produce instruments like Bösendorfer 290, that go below human hearing. With church organs vibration could be felt - is it the same for the piano? I though for a moment that perhaps it was designed for dogs but in spite of common "superior hearing" belief, dogs don't hear below 60Hz. It must have been for whales!!!

I believe dogs hear on the high end, not the low. High-pitched whistles and such.

For a quick listen to the lower notes from a Bosendorfer Imperial via iTunes, check out the song "Not Zero: In Three Parts" from Paul Bley's album "Not Two, Not One". It helps to have decent speakers for your computer. Pretty incredible sounding....not your momma's piano.