This cover doesn't have a pipe organ stamp, but rather includes a detailed photograph of an organ in an illustration on the left portion of the envelop. In philatelic parlance this is a cachet. Using Google translate I get "musical autumn." "Clujeana" doesn't translate, maybe because of missing diacritical markings. It may be referring to Cluj-Napoca, Romania, the second largest city in that country, and a possible site for a major autumn concert series. The third line of text specifically mentions the sixth Mendelssohn organ sonata, the one in which the chorale "Vater unser" features prominently. Below the image, the recitalist, a German, is named. It would seem the venue/sponsor of the recital went to a great deal of trouble to publicize the event. One wonders if other covers feature other concerts from the autumn season concert series. The postmark includes the same copy as the cachet, but also includes an image of Mendelssohn and his signature. The stamp itself (Scott 4159) is also from 1997, and depicts a monument and a cathedral, issued for a maximum card event that year, Balcanmax. Maximum cards are a rarified form of philatelic endeavore in which the stamp, the postmark, and the postcard or envelop all share a common theme or design element. In this case, the postmark and cachet are thus united, but the stamp foils the effort. Nonetheless, it's a nice piece of organ ephemera and a nifty way to publicize an organ recital. Without knowing the name of the building in which this pictured organ is located, I have not yet been able to track down more specific information about it. The postmark mentions the Transylvania Philharmonic orchestra, which is based on Cluj. If one could ascertain the venues in which they may perform, one may learn which organ this is.