At a concert, would the speed of sound be different for different frequencies? Why or why not?

3 answers

No, sound speed is independent of frequency. It just IS. It depends only upon the temperature (not even the pressure) of the air it is going through. As for "why?", that requires a physical derivation, with thermodynamics considered. An adiabatic heating and rarefaction process is assumed when a sound wave passes by.
You can find a derivation of the speed of sound in gases at:
http://www.grc.nasa.gov/WWW/K-12/airplane/snddrv.html

but it requires math and physics that is above grade 11 level.
At 25°C, sound can travel 100 meters across a football field in 0.29 seconds. Determine the velocity of these sound waves.