Bees, in contrast to people, do not hear with their ears, but they notice the sound with their whole body, especially with their antennas and sensitive body hair. The bees during their wagging dance produce the "sound" of 250 oscillations per second (250Hz). The movement of their wings creates this sound; it is also the "buzz", which we hear. This sound is about one octave under the concert pitch "a" of about 440Hz.
In every beehive there is a solid 100 cm² big "dance floor" near the entrance. It is composed from only empty cells, so that the floor can vibrate when a dancing bee begins to dance.
This vibration is a good means of communication, as it can be heard in every corner of the comb. The other bees would ignore a dance without vibrations.
Here the visitor can hit a tuning fork (250 Hz), then pluck the string and move the bridge until it is in tune with the tuning fork. This is the sound of the buzz of bees.