Ampico Roll 212541 - Strike Up the Band! 

Ampico Roll 212541 - Strike Up the Band! - Music by George Gershwin, words by Ira Gershwin with the collaboration of Millie Raush. Written for the 1927 musical 'Strike Up the Band.'
Ampico "B" roll played by 'Harry Shipman' (Edgar Fairchild?) and 'Victor Lane' (Adam Carroll?), released April, 1930. Klavier re-cut.
In this video are some views of the underside of the piano with the belly cloth removed, so you can see some of the mechanical and pneumatic gizmos that make the Ampico work.
Player piano mechanisms are sensitive to humidity. More humidity makes the leather valves and gaskets seal tighter against wood surfaces. Because of the change from dry winter weather (in the house) to damp spring weather, the piano was playing too loud, so I adjusted the suction pump spill spring. But then the piano played even louder, so I got underneath to see what was wrong (and took this video).
Turns out the bass crescendo pneumatic was closed all the way (so, maximum volume from the bass half of the piano) because I forgot to re-connect the 1B tube after adjusting the spill level (see it at 1:06 and 1:58 in the video). (It was fixed before the sound track for this video was recorded.)