Definition

1. Noun:
   • In music theory: The subdominant is the fourth degree (note) of a diatonic scale, or the triad (chord) built upon this degree. It is functionally important for creating harmonic tension that resolves to the tonic.

Usage

• The subdominant is a fundamental harmonic function in Western tonal music, often labeled with the Roman numeral IV in a major key or iv in a minor key.
• It is called the "subdominant" because it is the fifth below the tonic (in contrast to the dominant, which is the fifth above the tonic).
• It is commonly used in chord progressions, such as the ubiquitous I - IV - V - I (tonic - subdominant - dominant - tonic).

Examples

• Noun:
  • In the key of C major, the subdominant is the note F, and the subdominant chord is F major (F-A-C).
  • The composer used a move to the subdominant to create a feeling of gentle departure before returning home to the tonic.
  • A plagal cadence, often heard in hymns, involves a resolution from the subdominant chord to the tonic chord (IV-I).

Advanced Usage

• Subdominant Function: This refers to the role of chords that share a similar harmonic pull to the IV chord, such as the ii chord (the supertonic) or bVII chord in some contexts. They often prepare for or substitute for the dominant.
• Double Subdominant: A chord whose root is a fifth below the subdominant (e.g., the bVII chord in a major key, which is the subdominant of the subdominant).

Variants and Related Words

• Subdominant triad (n): The three-note chord built on the subdominant note.
• Plagal (adj): Relating to a harmonic progression or cadence involving the subdominant and tonic chords (e.g., the "Amen" cadence).

Synonyms

• Fourth degree: A more technical, scale-degree term for the subdominant note.
• IV chord: Specifically refers to the major triad built on the subdominant in a major key.

Related Terms (Not Phrasal Verbs or Idioms)

• Tonic: The first degree (I) of the scale, the central pitch and chord of a key.
• Dominant: The fifth degree (V) of the scale, the chord that creates the strongest tension resolving to the tonic.
• Diatonic Scale: A seven-note scale consisting of five whole steps and two half steps in a specific pattern (e.g., major or natural minor scale).

Noun

1. (music) the fourth note of the diatonic scale