These full year choir classes emphasize choral singing, music theory, listening, and performance. Ninth, tenth, eleventh, and twelfth grade students will comprise various classes according to achievement levels checked by audition. The classes may be composed of all males, all females, or mixed according to the number and distribution of voices available. The names of these groups differ with the high schools in which they are organized and participate in competitions such as UIL Concert and Sightreading. Students will have required rehearsals and performances outside regular school hours.