Transposing by target key involves selecting a target signature key and clicking the button.   The program allows to choose whether to transpose up, down, or to let it choose the closest keyboard position for the each transposed chord. 

This is done with the direction  buttons as described below.

Before transposing decide whether to transpose the whole song or just a range of chords.  If a range of chords, then these must be selected, see Selecting a Range of Chords.

To do the transpose choose one chord, usually the first chord of the song, and apply the following three steps:

Step 1:  select the transpose direction.

Step 2:  choose the target signature key.

Step 3:  transpose the chords.

Step 1 - select the transpose direction

case 1: transpose up

Click on the right arrow.  Use the left mouse button.

case 2: transpose down

Click on the left arrow.  Use the left mouse button.

case 3: for each chord, let the program decide the direction

If no arrow is selected, do nothing.  If one is selected, click on it again to unselect it.

The right and left arrows are mutually exclusive.  Both cannot be selected at the same time.  If one is selected, clicking on the other unselects it.

Step 2 - choose the target signature key

Click on the up or down arrows to set up the desired target signature.

Every time the arrow is clicked, the keyboard shows the result of transposing the current chord from its current key signature to the new key signature.

By displaying on the keyboard (but not on the chord table) the result of transposing the current chord to a new key, the program gives you the opportunity to appreciate the effect of changing keys.  If sound is turned ON, the you can hear this effect.

Step 3 - transpose the song

Click on the transpose button.  Both chords and melody notes of the song will be transposed to the target key.

When completed, all chords will display the new key signature:

It is important to keep in mind that transposition occurs on a chord by chord basis.  If all chords have the same initial signature key, then all chords will be translated by the same distance (same number of half steps).  But if the initial key of some chords is different from the rest, then the program will calculate for those chords what is the number of half steps required to end up at the desired target key.