AP Tuner is a highly accurate and responsive instrument tuner developed for use with a computer. Care has been taken to make the software as simple and functional as possible. Even with this goal in mind there are some areas that need extra explanation and detail to use the tuner to its full potential.
Official web site at:
Harmonics Graph Window:
The Harmonics Graph Window is a specialized graph used to show exact frequency of each harmonic over time for the note currently being played. Time is shown on the x-axis in seconds. The note and cent deviation are shown on the y-axis.
When a note played, its sound is a combination of one or more harmonics. The first harmonic is called the fundamental. Harmonics increase in frequency from the fundamental mostly as a integral factor of the fundamental frequency. For example, if A2 was played at 110 Hz. The second harmonic would be around 220 Hz, the third at 330 Hz.
Because it is useful to see all of the these harmonics superimposed ontop of the fundemental, the harmonics graph shows each harmonic divided by its harmonic number. This allows for a highly accurate visual represention of the harmonics all seen at the same time.
The left side of the window shows additional options for displaying two notes at once
The graph can be scrolled by pressing the left mouse button down on the graph area while dragging. To move only one axis, drag in the axis portion of the window. To zoom in and out, focus the graph window by left clicking on it and then use the mouse wheel.
To change which harmonic is highlighted, use the harmonic list of the left side, or left-click on the harmonic itself in the graph.