The ONU A Cappella Ensembles are the youngest choral ensembles on campus. Membership in one or more of the ensembles is by audition. Some of the ensembles sing in regional competitions with other similar ensembles from other schools. They each perform both on and off campus at least three times per year. (Each group has a name, but only one is set for 2007-2008.) Successful auditionees for these groups are independent singers with good intonation and pleasing vocal tone quality.

Barbershop Quartet: Four-part harmony, with the melody in the second-highest part. The music they sing follows the harmonic and tonal rules of the men's Barbershop Harmony Society and the women's Sweet Adelines International. Music in the barbershop style is performed from memory. Four Degrees North, the Women's Barbershop Quartet, has competed at the regional Sweet Adelines young women's quartet competition. There are currently two Men's Barbershop Quartets, both of which are looking for names and looking to compete this year.

Contemporary A Cappella Ensemble: A mixed ensemble that sings 4-8 part harmony with a "mouth drummer." Special vocal effects and the use of microphones and a "sound person" characterize this group. They sing a variety of music including rock, pop, jazz, gospel, show tunes and more, from memory. Competition is a possibility for this group, as well.

Madrigal Ensemble: A mixed ensemble of up to 16 voices that perform music from the Renaissance including madrigals and motets in a variety of languages. Unlike the previous ensembles, this group does not memorize their music, but perform the 3-6 part works from music, as it was done in the Renaissance. --