Josef Hofmann was, in addition to being the greatest pianist of the 20th
century, a prolific inventor and tinkerer.  He received many patents,
including one for the automobile shock absorber.  He worked with the
Steinway piano firm on different aspects of piano design, and suggested
the idea for their "accelerated action."  He was always mechanically-
minded, visited Thomas Edison's laboratory in 1888 and made the very
first cylinder recordings of piano music, when he was 12 years old!

Given the above, it's not surprising that Hofmann also tinkered with
the reproducing piano, although I hadn't heard about that before.  Most
likely, he was trying to improve upon an instrument that incorporated two
of his most intense interests; piano performance and mechanical devices.

Larry Lobel
Virtuoso Piano Service
Petaluma, California