Avivah,

The Synagogue did have an Organ (there is a great architectural
description of the Synagogue here:

http://www.sztetl.org.pl/en/article/warszawa/11,synagogues-prayer
-houses-and-others/3517,the-great-synagogue-of-warsaw-in-tlomackie
-street-tlomackie-4/?action=viewtable

Its last Cantor was quite famous as a singer. His name was
Gershon Sirota. He was killed by the Germans in 1943. There are
actually recordings of him singing that have survived- including
one of the Kol Nidre >from right before the Germans destroyed the
Synagogue. His profile is on geni.com but it is marked
private for some (or no) reason.

Seth MORGULAS
NYC