 Jennings prepared the choir to record Ravel's Daphnis et Chloé with the Minnesota Orchestra under the direction of Stanisław Skrowaczewski, and during his tenure, he arranged for several notable conductors to rehearse and lead the St. Olaf Choir in concert, including Polish composer Krzysztof Penderecki, Bach specialist Helmuth Rilling, British organist Simon Preston, and Robert Shaw.Jennings led the choir on twelve international tours, most notably to France (where he led the St. Olaf Choir, Strasbourg Philharmonic and international soloists in Bach's Mass in B minor for the opening concert of the 1972 Strasbourg International Music Festival), Norway (for the Bergen International Festival), and to Seoul, Korea, for the 1988 Summer Olympics Arts Festival.After his retirement from St. Olaf in 1990, he served as a visiting professor and choral conductor at Gustavus Adolphus College and the University of Arizona in Tucson.