Abstract: A stringed instrument plectrum that includes a second edge disposed perpendicularly with respect to a first edge, a rounded top portion disposed endwise opposite the first edge, a protruding pick portion disposed over a third edge, and a plurality of indentations disposed along the third edge, whereby said stringed instrument plectrum is more easily grasped within the hand of a musician, while yet enabling dexterous manipulation of a striking edge disposed upon a tip of the protruding pick portion, for rendering melody upon the relevant strings of a stringed instrument to which the present stringed instrument plectrum is applied when making music.

Abstract: A receiver circuit for a multi-frequency telephone dialling system has means for validating a received tone by making successive measurements of the tone period and validating the tone when m of n successive measurements lie within a single one of a number of given ranges and when, subsequently, l(< m) of n successive measurements of the tone also lie within that single range.