In music, the subdominant is the fourth tonal degree () of the diatonic scale.
[4] In the movable do solfège system, the subdominant note is sung as fa.
In Roman numeral analysis, the subdominant chord is typically symbolized by the Roman numeral "IV" in a major key, indicating that the chord is a major triad.
The term subdominant may also refer to a relationship of musical keys.
Modulation to the subdominant key often creates a sense of musical relaxation, as opposed to modulation to the dominant (fifth note of the scale), which increases tension.