Harmony

In music, harmony is about mixing different sounds to make new and interesting music. It looks at how different pitches or tones sound together, making things like chords, textures, and tonalities. Harmony has two parts: one looks at sounds that happen at the same time, and the other looks at how sounds change over time. It works with other music ideas such as melody, timbre, and form.

Harmony is very important in Western music. Musicians study how to put pitches together to make chords and how to change between chords to create chord progressions. People often say some combinations of pitches sound nice and smooth, while others sound rough. In many types of music, extra notes called “tensions” are added to chords to make the music more interesting. These tensions usually settle back into more comfortable sounds. This balance between tension and settling back helps music sound pleasant.

Etymology and definitions

The word harmony comes from the Greek word ἁρμονία harmonia, meaning "fitting together." An early book about harmony was written by Aristoxenus, called Elements of Harmony. He looked at how musical notes sound together and thought that what sounds harmonious depends on the listener, not just math.

Today, harmony in music means how notes sound together at the same time. Some people think harmony is only about notes that sound nice together, while others look at how notes follow each other. In Western music, harmony became more important around the year 1600. Music from other parts of the world, like Indian classical music, has its own ways to combine notes. These traditions often use a steady background sound called a drone instead of complex chords.

Historical rules

Early Western religious music often used special sounds to keep the music clear. These pieces were made in cathedrals, using the buildings to help create harmonies. As music got more complex, the way it was made changed. A new style using softer sounds became popular because it worked better for making 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 way. Coordinate harmony, used in older times like the Medieval and Renaissance periods, links chords directly to one another.

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 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. 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 special sound.

Chords and tension

Main articles: Chord (music) and Consonance and dissonance

In music, harmony uses chords. Chords are notes played together. Simple chords, called dyads, have two notes. Triads have three notes. For example, the notes C, E, and G make a C Major chord.

Chords can get more complex by adding extra notes. These extra notes are called tensions. They create interesting sounds. Later in the music, these tensions are resolved. This creates a balance between excitement and comfort in the music.

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 help us enjoy harmony, with certain areas responding more to chords that sound pleasing.

Consonance and dissonance in balance

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