Square grand pianos were the progenitors of the modern piano,
and continued in production for a while after the superior
concert grand style of Chickering or Steinway took over the
performance stage.  Reputed to have poor base tones, and actions
anywhere from poor to quite good, a lot of experimentation was
done in evolving these wooden machines and they are quite evocative
of the mid - late 19th c. era just before pianos finally assumed their
more orless fixed familiar "conventional" style.  Long term project.