A Dictionary of Music and Musicians/Pitchpipe
PITCHPIPE. A small stopped diapason pipe with long movable graduated stopper, blown by the mouth, and adjustable approximately to any note of the scale by pushing the stopper inwards or outwards. A pipe of this kind is so much influenced by temperature, moisture, force of blowing, and irregularities of calibre, that it can only be depended on for the pitch of vocal music, and is not to be trusted for more accurate determinations. A small reed pipe of the free species, in which the length of the vibrating portion of metal is controlled by a rotating spiral, is somewhat superior, and far less bulky than the older contrivance. It is known as Eardley's patent chromatic pitchpipe. Sets of single free reeds, each in its own tube, arranged in a box, forming a more or less complete scale, are to be obtained, and form comparatively trustworthy implements; if tuned to equal temperament they may be employed to facilitate pianoforte or organ tuning. All pitchpipes are however inferior in accuracy to tuning-forks: the only advantage they possess over the latter being their louder, more strident, more coercive tone, and the readiness with which beats are produced. No accurate tuning is practicable except by the principle of beats and interferences.
[ W. H. S. ]