Piano Tuner's Slide Rule

Never again be confused by the partial series, coincident partials, or check notes. Piano Tuner's Interval Slide Rule will easily show you all those simply by sliding your finger around on the screen. - Use the partial series to know what notes to listen for when tuning unisons. - Use the coincident partial setting to know where to listen when tuning intervals. - Use the check note feature to know for sure which check notes you need to use to tune any interval pure or wide or narrow, depending on your tuning system.