Chord tones (principal notes)
The notes belonging to the chord, as opposed to passing and neighbour notes.
What it means
Principal notes (Hauptnoten) are the notes of a melody or part that belong to the chord sounding at the time. Set against them are the auxiliary notes, such as passing notes and neighbour notes, which mediate between the principal notes or circle them but are not part of the chord.
Musical use
The distinction between principal and auxiliary notes helps in analysing a melody: the principal notes give the harmonic framework, the auxiliary notes the decorating figuration. The principal notes usually fall on strong beats, the auxiliary notes on weak ones. Especially in ornamented music the framework can be recognised this way by leaving out the ornaments.
Principal notes should be distinguished from non-chord tones, which include passing notes, suspensions, and neighbour notes, and from the main note of an ornament, the note circled by it. Both terms share the word “principal” but mean different things.
Performance practice
When practising, first recognise the principal notes of a passage and play them alone as a framework before adding the auxiliary notes. This gives you a secure picture of the harmony and lets you steer the figures purposefully toward the stressed notes.