NIKOLAI RUBINSTEIN (1835-1881) hand written letter in German-Oct.2, 1878 Moscow

Description

You are bidding on RARE hand written letter (5-1/4" x 8-1/4") in German signed by NIKOLAI RUBINSTEIN (1835-1881), dated Moscow, October 2, 1878.
Translation: (rough)
Dearest sir!
The concerts of the Russian Music Society will begin on November 3/15.
and will take place on all Fridays until December 15/27, then
after New Year from January 19/31 until February 2/15.
Reminding you of your generous promise, I take the liberty to ask if
you'd like to inform me as soon as possible if and when it will be possible
for you to come to us to Moscow.
In hopes of an affirmative answer I remain your sincerely greeting.
(I am unsure if Nicholai is speaking of Gregorian calendar and/or Russian orthodox calendar).
The Russian Music Society was disbanded in 1917.
Nikolai was the younger brother of Anton. Nikolai was a piano student of T. Kullak and gave annual recitals in Saint Petersburg. Also, composer, teacher and conductor.
Nikolai founded the Imperial Musical Society in Moscow, 1859 and became Director of Moscow Conservatory when it was founded in 1866 and remained it's director until his death.
He gave the first performance of Balakirev's, Islamey.
Among his students were H. Pachulski, Emil von Sauer, Alexander Siloti and Sergei Taneiev.