Part of the magic of a piano is that they are always surrounded by art. Designing them is an art. Playing them is an art. Recording them is an art. Tuning them is an art. And, it turns out, moving them is an art as well. Recently, I was able to watch as a grand piano was moved from a San Francisco apartment to a house. As always, it was enlightening to watch people who were experienced in the art.
As I noted in "Timber!", tools and infrastructure make jobs like this significantly easier, and provide more margin for error. For this move, the movers mounted the piano to a wooden sled (think of a dolly with no wheels), and used the sled as an interface with the world. They let the sled ride down the stairs, and not having to keep the piano off the floor allowed them to focus their efforts on staying centered in the narrow interior staircase, and keeping the descent under control.
As I noted in "Timber!", tools and infrastructure make jobs like this significantly easier, and provide more margin for error. For this move, the movers mounted the piano to a wooden sled (think of a dolly with no wheels), and used the sled as an interface with the world. They let the sled ride down the stairs, and not having to keep the piano off the floor allowed them to focus their efforts on staying centered in the narrow interior staircase, and keeping the descent under control.