How low is a piano?

The Bosendorfer 96 key piano (rarely recorded) extends an octave lower than A0 on an 88 key instrument. Many digital pianos and keyboards (much more commonly recorded) also offer an octave of pitch control for each key, so they can also reach down below A0.

Marty

Harmonics of the piano are much more complex than regular overtones. It resembles a little percussion instruments but it might also be due to tempered tuning of the piano: http://www.precisionstrobe.com/apps/pianotemp/temper.html

Benchmark Media technical director John Siau mentioned once that warm sounding gear (enhanced even harmonics) can make piano sound like out of tune. He also mentioned that because of crossovers in speakers the best piano sound can be reproduced with good headphones.

The Bösendorfer 290 does not extend a full octave below the standard 88 key piano. The 88 key piano goes down to A0, the 97 key Bösendorfer 290 goes down to C0, approx. 16 Hz, an additional 9 keys, a little more than half an octave extra.

http://www.boesendorfer.com/en/model-290-imperial.html

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

Actually it's 41Hz in standard tuning.