Fact or fiction?

I have heard twice in my lifetime,(Iam very near 50) once in southeast Missouri where I grew up (in about 1970) and once here in the panhandle of texas (recently) that in the 50's hot rodders would string a piece of piano wire tightly across the end of their talpipe on a straight exhaust car and when ya let off the gas from high rpm the resonation would break plate glass windows.
Any truth to this???
Thanks for your input!
Bill

Why not try it??

http://www.jalopyjournal.com/forum/showthread.php?t=310453&highlight=piano+wire

I was just curious if anyone else had ever heard of it....I do have a slant six in the ol 84 truck tho.......and it is kinda loud with a flowmaster copy...hummm