Beats occur when two sounds with similar frequencies are played together, resulting in a regular pattern of louder and softer tones. The document discusses beats, noting they are produced by waves with similar frequencies and define the downbeat and upbeat of music. It then asks what the beat frequency would be if a 200Hz and 206Hz tone were played together. The answer is that the beat frequency would be 3Hz, calculated as (206-200)/2, meaning the louder and softer pattern would occur 3 times per second.