Chord Progression Analyzer
Analyze harmonic tension in chord progressions using root note, scale type, degree, and voicing. Use it when composing or arranging music to quantify how tense or resolved a chord feels within a key.
About this calculator
Harmonic tension describes how much a chord pulls away from the tonal center of a key. This calculator estimates a tension value using the formula: tension = round((rootNote + (chordDegree − 1) × scaleFactor) × voicing × 10) / 10, where scaleFactor is 2 for major scales and 1.7 for minor scales. The root note provides a numeric pitch baseline, the chord degree (I through VII) determines position within the scale, and the voicing multiplier reflects how open or dense the chord's interval structure is. Higher values indicate greater harmonic tension — chords that feel unresolved or dissonant — while lower values suggest stability and rest. Composers use tension curves to plan when to create drama and when to resolve back to the tonic.
How to use
Suppose you are writing in C major (rootNote = 0), using the V chord (chordDegree = 5), with a standard close voicing (voicing = 1.2). Apply the formula: tension = round((0 + (5 − 1) × 2) × 1.2 × 10) / 10 = round((0 + 8) × 1.2 × 10) / 10 = round(96) / 10 = 9.6. This high tension value confirms that the V chord strongly wants to resolve back to I. Try chordDegree = 1 with the same inputs to see the tonic's low tension value and compare.
Frequently asked questions
What does harmonic tension mean in a chord progression?
Harmonic tension measures how much a chord resists resolution to the tonic. Chords built on the 5th degree (dominant) carry the most tension because their tritone interval strongly implies motion back to the I chord. Understanding tension helps composers control the emotional arc of a piece — building anticipation and delivering satisfying resolutions.
How does scale type affect chord tension values?
Major scales use a scaleFactor of 2, which spreads chord degrees further apart in tension space, creating a wider dynamic range between stable and unstable chords. Minor scales use 1.7, reflecting their naturally darker, more ambiguous harmonic character where tension differences between degrees are subtler. Choosing the right scale type ensures the calculator's output matches the tonal language of your composition.
When should I use chord voicing adjustments in the analyzer?
Voicing multipliers should be adjusted when you change how a chord's notes are arranged across the register — for example, open voicings with wide intervals feel more spacious and often less tense than close-position chords. A voicing value above 1 amplifies the tension score, while values below 1 reduce it. Use higher voicing multipliers when analyzing dense jazz chords or orchestral clusters, and lower values for simple triads.