Seventh chords play an integral part in piano music across genres and moods. Learning how to identify these chords will open up new musical opportunities for any pianist.
A seventh chord’s underlying chord is always a major triad, while its quality depends on how its seventh interval relates to the root.
Major
As part of your chord-learning experience, it can be beneficial to first break them down into their individual components and understand their theory before applying it to play songs – this way you’ll pick up new riffs, memorize song lyrics and develop an understanding of how best to utilize each chord in your music.
Seventh chords are four-note triad chords with the added interval of a seventh note from their roots – making them dissonant by nature while adding emotion and tension to your progressions.
Major seven chords are the most widely known type of seventh chord. To create this chord, take a major triad and add an interval above its root which creates C-E-G-B; often written as Cmaj7 or C7. Alternatively, write minor-major seventh chords as either Cm(maj7) or Dm(maj7) both with identical notes but distinct quality characteristics.
Minor
Building seventh chords gives you the flexibility of altering their qualities by shifting the interval relationships among their root note, third note and fifth note – creating a variety of different chords!
Minor 7th chords are composed from minor triads with the addition of a major seventh above their root note for an intense sound that contrasts well with darker minor 6th chords.
Minor major 7th chords can also be created using a major triad and by adding an additional minor seventh above its root note. These chords are common in jazz, R&B and blues music and give songs a more mellow vibe.
Some seven-chord intervals are not treated equally; for instance, chords constructed on scale degrees 11, 22 and 33 are rarely employed in tonal music as their dissonant seventh would undermine its stability; when used however, these chords usually resolve down by one step to circumvent this problem.
Dominant
As the first dominant seventh chord to regularly appear in classical music, a dominant seventh has an unmistakable sound. Common in modern pop and soul music, as well as older pieces like Debussy’s romantic “Claire de Lune”, it stands out with its distinct sound.
Dominant seventh chords consist of a major triad with an added seventh interval above its root that creates tension that needs to be released by toning down or refining it.
So it is crucial for musicians to recognize the sound of a dominant seventh and use this knowledge in creating successful chord progressions.
Secondary dominant seventh chords offer a novel way of creating tension in a progression. Their key distinction from regular dominant seventh chords lies in the way that their seventh interval is reduced by half-tone to create an equivalent major sixth-enharmonic harmony, giving an effect more similar to that of its tonic chord.
Sustained
Although dissonant in nature, seventh chords can be an effective tool to add emotion and tension to a composition. They often act as the culmination of a progression or cadence; although less frequently found than major or minor triads, seventh chords will likely appear somewhere within most songs at some point.
One easy way of recognizing seventh chords is using their Roman numeral. This indicates what scale degrees they’re built on – for instance I7 indicates a triad with a major seventh and i7 indicates one with diminished seventh.
Identification of seventh chords by their intervals is another effective means. You can do this by comparing it with the third and fifth intervals found in major, minor and dim triads; sustained chords such as sus4+maj7 are commonly used as examples where harmony between two chords has been lost before being resolved through shifting toward unison or perfect fifth intervals.