[citation needed] Having been a very young soldier in a heavy field artillery regiment in Aqui for four years, Giacomo took part in the Great War as it was drawing to a close and joined his father Leandro in Siena immediately after he was discharged.
[4] Leandro Sr's most significant idea, which led his workshop to excel and to revive the great tradition of Italian violin making in the early 1900s, was to organise production in such a way as to overcome the concept of the all-rounder luthier.
[citation needed] The violins made in the Bisiach workshop almost all ended up making it to America or Japan, under the careful supervision of the master craftsmen of the Milan Fine Arts Department who certified their authenticity and value.
[citation needed] Giacomo Bisiach's expertise in the development of the instrument was such that the musicologist, artist and engraver Benvenuto Disertori, professor of Renaissance musical palaeography in Cremona and Parma, defined him as the "psychiatrist of the violin, because he knows how to put its soul in order".
[citation needed] The renowned qualities of Giacomo were appreciated by concert performers such as Pablo Casals, Yehudi Menuhin, Massimo Amfiteatrof, and Nathan Milstein, names of just a few of the most famous, who constantly called upon his services to have the most top-performing instruments.