減七(導音)

In music, the subtonic is the degree of a musical scale which is a whole step below the tonic note. In a major key, it is a lowered, or flattened, seventh scale degree (). It appears as the seventh scale degree in the natural minor and descending melodic minor scales but not in the major scale. In major keys, the subtonic sometimes appears in borrowed chords. In the movable do solfège system, the subtonic note is sung as te (or ta).