Harvard ended compulsory morning chapel in the late 19th century.

But more than 100 years later those chapel services continue, supported by one of the strongest collegiate choral traditions in the country.

Five days a week, 18 members of the University Choir sing for a congregation in Memorial Church's Appleton Chapel. Every Sunday during term time, the full choir of 40 voices sings for the morning service.

Leaders say the University Choir is more diverse than ever--members' faiths range from Mormonism to Judaism to atheism. Yet the student members arrive at the church by 9:45 a.m. every Sunday morning to sing sacred Christian music to a church full of Protestant worshippers.

But while religious faith motivates few, other factors succeed in drawing students to the choir and strengthening the sacred tradition of a secular University.

University Choir members are among the only student singers at Harvard paid for their work. The salaries, combined with efficient rehearsals and ever-changing material, give the group a sense of professionalism and unity.

The University Choir has been a Harvard institution since at least 1834, the date of its earliest-known constitution.

Tonight at 8 p.m. in Sanders Theatre, the choir will perform Mass in D by John Knowles Paine, accompanied by the Mozart Society Orchestra. Although Paine was the first University organist and choirmaster, serving from 1862 until 1906, his Mass has never been performed on campus.