tonights the night, page-61

re: min maj 6ths Ok so say for example I hit c and a, to create a major 6th.

Does the c string vibrate at the c frequency and the a string at the a frequency and the composite that is produced vibrate as if it where a major 6th?

I just need to get my head around what is actually happening to the strings when these notes are hit, i.e. how is their vibration changed.