Mater Ecclesiae Roman Catholic Church will celebrate its 18th annual Mass of thanksgiving on the feast of the Assumption, Wed., Aug. 15, at 7 p.m. at the Cathedral Basilica of SS. Peter and Paul, located at 18th Street and Benjamin Franklin Parkway in Philadelphia.

The Reverend Robert C. Pasley, KCHS, rector of Mater Ecclesiae, will be the celebrant.

The Mass will feature the Ars Laudis Festival Chorus and Orchestra, conducted by Dr. Timothy McDonnell. Cantor Nicholas Beck, a graduate of Westminster Choir College, will direct the singing of the Gregorian Propers.

Mater Ecclesiae celebrates this feast each year by the use of the great treasury of sacred music, especially the less frequently prayed polyphonic Masses.