There are two dialog boxes for interval 1) the distance between two pitches 2) two notes combine to form an interval selection. Switch between the two by pressing the push-button Scale-Tone Intervals from either dialog box.
Scale-tone (diatonic having to do with the seven note scale) intervals are built using only the tones of the scale a group of pitches arranged from high to low covering one octave of the key signature. Scale-tone intervals measure the distance between notes of a scale. For example, a 3rd could be either Major or minor depending on where it is in the scale.
Here is the other Intervals dialog without SCALE-TONE Intervals selected:
Any combination of intervals may be selected for practice drills.
Intervals may be presented ascending, descending, or harmonic an interval or chord where all notes sound simultaneously. It is also possible to start all intervals on the same pitch.
When Start on Same Pitch is selected, play a note before the drill begins to set the lowest pitch.
With the by Ear drills, choose "Play Harmonic After" to hear each interval twice. The second hearing will be the harmonic form. For example, given a minor third ascending, you would hear the two separate pitches then both together.
Compound intervals are larger than an octave. For example, a M2 + P8 make a M9. It is important to set the portion of keyboard, fingerboard, or staff range large enough.
To read the interval correctly in staff notation, one must take into account the sharps or flats of the key signature.
see also: Interval Naming