<p>how do you find the number of beats between two instruments if you are given the frequency of one instrument?</p>
<p>You can’t. You need both frequencies (say f1, f2). Then, beat frequency = |f2 - f1|. This phenomenon only occurs for small enough differences such that you get a sinusoidal envelope for the sum though.</p>
<p>so if it says “2 tuning forks of 132Hz and 137Hz how many beats are heard per second if both are sounded simultaneously?” the answer is 5?</p>
<p>^ Exactly :D</p>