Several months ago, I wrote about Paul Jacobs, the 30-year old chairman of the Juilliard organ department, who had just been named to the 2007 William Schuman Scholar's Chair, awarded annually to an artist-educator who has made significant contributions to the Juilliard community. The chair calls on the recipient to deliver three lecture-performances througout the year, the last of which will be held tomorrow night at the Church of St. Mary Virgin, in Times Square. Jacobs will be performing Olivier Messaien's Livre du Saint Sacrement, a towering masterpiece of the 20th century and one of the great works ever written for the organ. The lecture begins at 730p, with the performance immediately following; admission is free.