# Chords & Harmony, Music theory

Triads, seventh chords, and progressions

Harmony is music stacked vertically. Learn how chords are built from intervals, why some progressions feel resolved, and how functional harmony creates the emotional arc of a piece.

Intermediate · 5 lessons · approximately 75 minutes of material (not a mastery deadline).

## Before this module
- [Intervals](/learn/theory/intervals), The distance between any two notes

## What this module covers
1. **Building Triads**, Three-note chords, the foundation of all harmony (14 min)
2. **Chord Quality**, Major, minor, diminished, and augmented chords (15 min)
3. **Chord Progressions**, How chords move and create musical narrative (16 min)
4. **Functional Harmony**, Tonic, subdominant, and dominant, the three pillars (14 min)
5. **Seventh Chords**, Adding the seventh for color and tension (16 min)

## What comes next
- [Ear Training Basics](/learn/theory/ear-training), Hearing what you see, seeing what you hear

## Where should I start with chords & harmony?
The curriculum places Intervals before this module. Review those topics if they are unfamiliar. The first lesson is “Building Triads”: Three-note chords, the foundation of all harmony. The order is a study guide, not proof that every learner needs the same pace.

## How long is the chords & harmony module?
The 5 listed lessons total approximately 75 minutes of material. That estimate describes lesson content, not the practice time needed to become comfortable with triads, seventh chords, and progressions. Revisit one task at a time and use feedback from a teacher where physical technique is involved.

## What can I try here without an account?
The chords & harmony description, lesson sequence and prerequisite links are public. There is no full worked lesson sample for this module yet. The linked public tools and references are free. A free account includes the complete five-lesson foundation module in each instrument and five lessons in music theory, with saved progress and no expiry. Later lessons require the relevant paid package.

## Continue in Arco
The complete five-lesson foundation module in each instrument and five music theory lessons are free with an account, including saved progress and no time limit. Later lessons require the relevant paid package. Public samples do not assess your physical technique or certify exam readiness.

[See packages and pricing](/pricing) · [Back to the music theory curriculum](/learn/theory)

Canonical source: https://arcosounds.com/learn/theory/chords