The word key tone is often used in music to refer to the main note or chord that a song is based on. There are several synonyms for this term, such as tonic, root note, and anchor pitch. The tonic note is the first note of the scale and is the most stable, while the root note is the note that the rest of the chords are built around. The anchor pitch, on the other hand, is the note that helps keep the melody and harmony together, providing stability throughout the song. Other synonyms for key tone include home pitch, dominant note, and leading tone, all of which are essential elements in creating a well-structured musical composition.