To give a play by play of the pictures above, the first is a lower register recording. Starting from the left side, the first cloudy section is the sound of the dampers going up causing the strings to quietly resonate. Then, the dark yellow is a key played in the lower register. You can see how the upper harmonics die off with time, and the "aura" cloud above the yellow are the sympathetic resonances caused by the dampers being up and having all of the strings able to vibrate. Finally, on the right side, you can see when I released the pedal and the strings stop vibrating. The vertical column is the dampers coming down. What makes this recording perfect is that there is no click sound from the action, there is no pedal noise, there is nothing. That's because this recording was done on a 280cm piano at the bass end, with the particular mic capsule pointed away from the piano. It didn't pick up any natural amplification of noise from operating the piano itself.
The other picture was a mic capsule closer to the action, and closer to me. There are exhales, action noise, my computer's fan, my host rubbing hands together or something, and some inadvertent clicks that could be accidentally touching mic cables or the piano itself.
