The Vocal Music Department at Sioux City East offers a comprehensive choral program serving a population of over 1,400 students in grades nine though twelve. The East High Choirs present four concerts each year, in addition to an authentic Renaissance Madrigal Dinner and biennial musical theatre production. With eight ensembles, the program offers students a variety of experiences, all rooted in healthy singing and music literacy.

The premier ensemble, the Chamber Choir focuses primarily on unaccompanied repertoire and has performed in some of our country's finest venues, including four appearances in Carnegie Hall. They have earned awards at competitions throughout the country, including those in Los Angeles (2008), Chicago (2010, 2014), La Crosse (2012, 2016), and Cincinnati (2017). In 2013, they were a featured ensemble in the University of South Dakota's Vocal Arts Festival, and in 2016, premiered a work that earned First Prize in Morningside College's Choral Composition Competition. In December, 2018, they premiered a new work - “Winterlight” - by American composer, Connor Koppin. Outside their own ensembles, students annually participate in festivals including All-State, ISU Honor Choir, Dorian Honor Choir, UNI Women Sing, and State Solo/Ensemble Contest. In 2019, they performed as the 4A Featured Ensemble at the third annual Iowa Choral Showcase, sponsored by the Iowa Choral Directors Association, and in 2020, accepted an invitation to perform at Luther College’s Dorian Vocal Festival.

East's show choirs are active on the competition circuit, and the program constitutes the largest extra-curricular organization in Sioux City. Since 1989, The Headliners have garnered more than 50 Grand Champion awards and numerous awards for Best Vocals, Best Choreography, and Best Band. They have been recognized by Parade Magazine as one of America's Favorite Show Choirs (top 3, 2010), featured in choreographer Mike Weaver's book, Sweat, Tears, and Jazz Hands: The Official History of Show Choir From Vaudeville to Glee, and named "Most Decorated" in Iowa (2016). In 2021, they appeared virtually on the National Convention of the American Choral Directors Association. In addition to competing, the EHS Show Choirs annually host their own competition - "Sing All About It!" - and a Dinner Theater that has raised more than $100,000 to the benefit of students in EHS Show Choir. In 2019, “Sing All About It!” won the Fame Aspire award for Best Regional Competition, having also been nominated in both 2017 and 2018.

Graduates of East High School have gone on to study music at institutions around the country, and are successfully working in numerous facets of the industry, including teaching, performing, arranging, producing, and managing.