Question 14.AP.4: WHY ARE INSTRUMENTS WARMED UP? Why do the strings go flat an...
WHY ARE INSTRUMENTS WARMED UP?
Why do the strings go flat and the wind instruments go sharp during a performance if an orchestra doesn’t warm up beforehand?
Without warming up, all the instruments will be at room temperature at the beginning of the concert. As the wind instruments are played, they fill with warm air from the player’s exhalation. The increase in temperature of the air in the instruments causes an increase in the speed of sound, which raises the resonance frequencies of the air columns. As a result, the instruments go sharp. The strings on the stringed instruments also increase in temperature due to the friction of rubbing with the bow. This results in thermal expansion, which causes a decrease in tension in the strings. With the decrease in tension, the wave speed on the strings drops and the fundamental frequencies decrease, so the stringed instruments go flat.