Illiana has four choirs: Concert Choir, A Capella Choir, Women’s Chorale, and Chamber Singers.
- Concert Choir: Concert Choir is a mixed choir made up of freshmen-senior students. It is designed to develop within students the fundamentals of choral music.
- A Capella Choir: A Capella Choir is a select choir designed to further increase choral skills and to develop a greater understanding of, and appreciation for, the art of music.
- Women’s Chorale: Women’s Chorale is a select women’s choir with an emphasis on proper tone production, development of the SSA sound and developing a greater appreciation for the art of music and women’s choral literature.
- Chamber Singers: Chamber Singers is an extra-curricular choir of a select group of singers, generally juniors and seniors, who rehearse traditional madrigal music as well as sacred pieces suitable for 8 to 16 singers. The group rehearses on its own and is in constant demand to sing in the community.