Sinfonietta is an auditioned after school chamber orchestra that rehearses every Tuesday from Late October through March from 3:45-5:15. Sinfonietta is the most selective ensemble at LZHS, and is open to any student, 9-12th grade. The audition  includes one major and one minor scale from the ILMEA scale list and a prepared piece no longer than 5 minutes.

Sinfonietta performs at the Winter Orchestra Concert in December and their own Sinfonietta concert in March. Students also have the opportunity to perform in festivals and other events throughout the year.