The Display Area

The central area of Intonia's screen is for display of sounds, as shown below:
In the default Composite View, pitch is shown as the height of the trace, amplitude (or loudness) is shown as the thickness of the trace, and relative intonation is shown as color: red for sharp and blue for flat.

In the Composite View, the left edge of the window resembles a piano keyboard. The A-440 key has a green dot. The horizontal lines vary in brightness depending on the key signature: the tonic lines are the brightest, followed by the fifth, the third, the diatonic notes, and the accidentals.

The horizontal axis is time, and the times are labeled at the top of the central area. If the amount of music on the tape is more than the width of the display, you can place the mouse over the numbers at the top of the screen and you can drag the display right or left.

A red vertical line called the "needle" indicates the instant being played or recorded. Unless recording or playback is active, you can click the mouse on the screen to set the position of the needle.

You can select an interval of time in the recording by clicking and dragging the mouse horizontally, or by clicking once to set the needle at one end of the selection then shift-clicking to set the other end of the region. The selected region is highlighted in reverse video. Click anywhere else to remove the highlighting.