NOTE: For me this one doesn't work on GeoGebraTube. Download it and run it on your own computer and it should work.[br][br]This is a bare-bones structure for doing various sound/harmonic demonstrations.[br][br]The frequencies are fundamentals for two different sound waves. Variables below each set the amplitude (ending in "a") and the phase (ending in "f") for the first 7 harmonics. [br][br]When the wave-viewing window is set so that audible beats show well, the time axis is completely hidden. Use the radio button by the function to hide it (empty circle) and then stretch or shrink the horizontal axis as needed before turning display of a wave back on.