Piano Tuners Interval Slide Rule App
The Piano Tuners Interval Slide Rule is an indispensable app for anyone who is trying to learn how to tune pianos by ear and may have some difficulty knowing all the partials, coincident partials, and check notes of the different notes/intervals on the piano.
Partials - Whenever any string is played it produces a series of frequencies called partials. Piano tuners must know what these frequencies are because when we tune unisons, which are just two strings of the same frequency, all of the partials in each partial series must line up to produce no beating. (Beating occurs when frequencies are close but not exact.) Knowing where to listen is required if a piano tuner is going to be able to tune clean unisons.
Coincident Partials - When an interval is played on the piano, each interval note produces its own partial series. If there is a partial that belongs to both partials series, we say that that partial is a coincident partial. If each coincident partial has the same frequency there will be no beating and we say the interval is pure. If the coincident partial frequncies are close but not exact, then the interval will be beating and will not be pure; it may be wide or narrow. Sometimes the piano tuner wants the intervals to be pure; sometimes wide, sometimes narrow.
Check Notes - Check notes are very powerful. They allow piano tuners to measure if an interval is pure or wide/narrow by the smallest amount. Without check notes, many non-pure intervals are impossible to tell if they are wide or narrow.
If you are learning to tune pianos or are an experienced piano tuner who has trouble naming intervals, coincident partials, or check notes, you NEED this app!