Harmony

In music, harmony is the idea of combining different sounds to create new and interesting musical ideas. It looks at how different pitches or tones sound together, forming things like chords, textures, and tonalities. Harmony has both a "vertical" part, which looks at how sounds fit together at the same time, and a "horizontal" part, which looks at how they change over time. It often works together with other musical ideas such as melody, timbre, and form.

Harmony is especially important in Western music. Musicians and theorists study how to put individual pitches together to make chords, and then how to move between chords to create chord progressions. This has been a subject of study for many centuries.

People often describe certain combinations of pitches as sounding pleasant, beautiful, or "consonant," while others may sound rough or "dissonant." In many kinds of music, extra notes called "tensions" are added to chords to create interest. These tensions usually resolve back to more comfortable sounds. Balancing these moments of tension and resolution helps music sound pleasant overall.

Etymology and definitions

The word harmony comes from the Greek word ἁρμονία harmonia, meaning "fitting together." One of the earliest books about harmony was written by Aristoxenus, titled Elements of Harmony. He studied how different musical notes sound together and believed that what sounds harmonious depends on the listener's ear, not just math rules.

Today, harmony in music means how notes sound together at the same time. Some people think harmony only includes notes that sound nice together, while others focus on how notes are played one after another. In Western music, harmony became more important around the year 1600, but music from other parts of the world, like Indian classical music, has its own ways of combining notes. These traditions often use a steady background sound called a drone rather than complex chords.

Historical rules

Early Western religious music often used parallel perfect intervals to keep the clarity of the original plainsong. These pieces were created and performed in cathedrals, using the special sounds of the buildings to make harmonies. As music became more complex, the use of parallel intervals changed. Instead, a new English style using thirds and sixths became popular because it had a sweeter sound and worked better for creating more detailed musical lines.

Types

Harmony can be divided into different types based on how sounds are combined. One way to classify harmony is into coordinate and subordinate harmony. Subordinate harmony is the type most commonly used today, where chords relate to each other in a specific, goal-directed way. Coordinate harmony, used in older times like the Medieval and Renaissance periods, links chords directly to one another without a clear sense of direction.

Another way harmony is categorized is by how close or far apart the notes in a chord are. Close harmony uses chords where the notes are close together, while open harmony spreads the notes out more. Harmony can also be described by the intervals, or distances between notes, in the chords. For example, many chords in Western music are built using the interval of thirds. Other types include quartal and quintal harmony. A unison, where the same note is played or sung multiple times, is also a type of harmony and is often used in orchestration and pop music.

Intervals

An interval is the distance between two musical notes. For example, in the tune "Twinkle Twinkle Little Star", the first two notes and the next two notes form an interval called a fifth. This means if the first note is C, the next note in the interval will be G.

Intervals are important in creating harmony, which is when notes sound together to make music. In music, there are twelve main notes, and by using different intervals between them, we can create many kinds of chords and tunes. For example, a C chord uses the notes C, E, and G together. These intervals help give music its unique sound and feeling.

Chords and tension

Main articles: Chord (music) and Consonance and dissonance

In music, harmony often uses chords, which are combinations of notes played together. The simplest chords, called dyads, have just two notes, while triads have three. For example, the notes C, E, and G make a C Major chord.

Chords can become more complex by adding extra notes, called tensions, which create interesting sounds. These tensions are usually resolved later in the music, leading to a pleasing balance between tension and relaxation. This way, music can feel exciting but still comfortable to listen to.

Perception

Harmony is how we hear chords and sounds together. When notes blend well, we call this consonance. For example, the octave and perfect fifth sound smooth because their tones match closely. Major chords, like a major triad, often sound more united than minor chords.

Our ears can also sense when sounds clash, creating roughness. Small intervals, such as the minor second, can sound harsh because the notes are too close together in pitch. Over time, listeners get used to new chord combinations, making them sound more pleasant. Our brains also help us feel harmony, with certain areas responding more to chords that sound pleasing.

Consonance and dissonance in balance

The balance between harmonious and tense sounds is important in music. It helps create excitement and interest in a piece, just like a good story needs both happy and exciting parts to keep you engaged. Famous musician Frank Zappa once compared music that stays the same all the time to a movie with only good characters — it wouldn’t be very interesting!