Key (music)
Definition
A key in music is a group of pitches, or scale, that forms the basis of a music composition in classical, Western art, and Western pop music. The group features a tonic note and its corresponding chords, also called a tonic or tonic chord. Each key comes with its own characteristic emotional quality, often used by composers to stir specific feelings or moods in the listener.
Overview
In music theory, the key of a piece is the group of pitches, or scale, that forms the basis of a music composition in classical, Western art, and Western pop music. The group features a tonic note and its corresponding chords, also called a tonic or tonic chord. Each key comes with its own characteristic emotional quality, often used by composers to stir specific feelings or moods in the listener.
History
The concept of musical keys developed over time, starting with modes in ancient Greek music. The Greeks used a system of tetrachords, four-note segments, which they combined to create a range of different scales. These scales, or modes, were the precursors to our modern concept of keys.
In the Middle Ages, the church modes were developed, which were the first scales to be used in Western music. These modes were later replaced by the major and minor scales, which form the basis of most Western music today.
The concept of keys became more complex with the development of tonality in the Baroque period. This was a system where one note (the tonic) was the central point of a piece of music, with all other notes and chords functioning in relation to it. This concept of tonality is still the basis of Western music today.
Major and Minor Keys
In Western music, a piece of music is usually in either a major key or a minor key. These two types of keys are defined by the intervals between the notes in their scales.
A major key is defined by the specific pattern of whole and half steps between the notes in its scale. This pattern is Whole-Whole-Half-Whole-Whole-Whole-Half. The major key is often described as having a happy or joyful quality.
A minor key, on the other hand, has a different pattern of intervals: Whole-Half-Whole-Whole-Half-Whole-Whole. The minor key is often described as having a sad or melancholic quality.
Key Signature
The key signature of a piece of music is the collection of sharp or flat symbols placed together on the staff at the beginning of a piece of music. The key signature indicates the key of the piece; specifically, it shows which pitches will be sharp or flat throughout the piece.
Modulation
Modulation is the process of changing from one key to another within a piece of music. This can be done in a variety of ways, such as through a pivot chord (a chord that is common to both the initial key and the key to which the music is modulating), or through a sequence of chords that leads to the new key.
Transposition
Transposition is the process of moving a piece of music from one key to another. This can be done for a variety of reasons, such as to accommodate the range of a singer or instrumentalist, or to change the mood of a piece of music.