For years, Phoenix Symphony musicians have used a unique educational tool – the “Velcro Cello,” a take-apart instrument that reveals the intricate engineering behind the beautiful sound of string instruments. Created by a Phoenix Symphony musician, the Velcro Cello is a tool that musicians and teachers can use to teach the principles of design and acoustics to students. During Mind Over Music® lessons, it is also used to demonstrate the physics and engineering that go into the cello’s structure.
On string instruments, every element plays a crucial role, from the concave front and back crafted from specific wood like spruce and maple to the distinctive, S-shaped ribs (sides). The curves contribute to the cello’s resonance and structural integrity. The choice of wood itself is an engineering consideration. Spruce, known for its lightness and strength, is often used for the top, while maple, denser and more resonant, forms the back and sides. This combination optimizes sound production.
Unseen components like the sound post, a small dowel wedged inside the cello, are critical. It transmits vibrations from the bridge to the back, influencing the instrument’s tone and volume. The strings, typically made of steel or gut, vibrate at specific frequencies, creating musical notes. These vibrations are transferred to the bridge, then to the body of the cello, where they resonate and project outwards.
The bow is also a marvel of engineering. Its curved stick, traditionally made of Pernambuco wood, provides the necessary flexibility and strength. The horsehair, stretched taut across the bow, interacts with the strings, causing them to vibrate. The angle and pressure of the bow, along with the rosin applied to the hair, all affect the sound.
The Velcro Cello allows students to examine these components individually, understanding how they work together to create the rich, complex sound of a string instrument. It transforms abstract concepts of acoustics and engineering into tangible experiences, inspiring a deeper appreciation for both music and the science behind it. The Phoenix Symphony’s use of this unique educational tool during our Mind Over Music® collaborations fosters a new generation of music lovers and scientifically curious minds.
