Back in 1981 a recording was released, Music for Christmas, featuring the Eastman French Horn Choir and the Eastman Trombone Choir. The first track on that album is Cor Carols, a work arranged by Leonard P. Schwartz. Schwartz was a horn student at Eastman at the time and is listed among the student performers.
According to the record jacket the Eastman French Horn Choir was established in 1969. I was a student at Eastman from 1984-86, and this work was a key work among the works we performed at the annual Eastman Holiday Sing, all of them being works in 8 parts performed by two antiphonal horn choirs with all parts at least doubled, with three first horns in each choir and four fourth horns each for a total of 22 horns when I was there. To this day this general arrangement of 8 part antiphonal horn choir writing remains my favorite horn choir setup.
As to Cor Carols, it is an inventive work that combines Christmas favorites with orchestral excerpts. By the time I was there Verne Reynolds had re-worked the ending compared to the recording. I have been told that he subsequently re-worked the piece several times. The video below (direct link here) is I believe the final iteration of the work, as performed by the Eastman Horn Choir at the Holiday Sing in 2010, conducted by Peter Kurau. It is actually pretty heavily re-written, I personally miss the original opening, but it is nicely performed and you do get the feel of being there to be sure!
Want to hear it live? I believe it will be performed next week at the Eastman Holiday Sing, which I see listed as being held on Friday, December 14, 2012 from 12:00 PM to 1:00 PM at the Eastman School Main Hall. One not to miss if you are in the Rochester area! More on the Eastman Horn Studio may be found here.