Chapter three: pitch collections, scales, and major keys
chromatic and diatonic collections
Chromatic collections contain one of each possible pitch-classes; these form diatonic collections -seven different letter names in a particular arrangement.
Scales: ordered pitch-class collections
This pitch, C, provides the foundation for a special type of diatonic collection called a major scale.
*Important side note: A major scale may begin on any pitch. It must include each of the seven letter names, such as the example below:
*Important side note: A major scale may begin on any pitch. It must include each of the seven letter names, such as the example below:
A scale degree is each pitch of the scale. When you write or play a scale, each note, its beginning note is referred to as the tonic, and is usually repeated one octave higher at the end. A solfege assigns each scale degree a syllable - do, re, mi, fa, sol, la, ti, do. A major tetrachord is a division of a scale into two four-note groups.
*Important side note: A half step spelled D-D sharp is a chromatic half step, the same letter name plus a chromatic alteration. However, a half step spelled D-E flat is a diatonic half step: different letter names for adjacent pitches in a diatonic scale.
*Important side note: A half step spelled D-D sharp is a chromatic half step, the same letter name plus a chromatic alteration. However, a half step spelled D-E flat is a diatonic half step: different letter names for adjacent pitches in a diatonic scale.
major keys
A key signature shows what pitches are to be sharped or flatted throughout a work. It appears at the beginning of each line of a score, right after the clef. The meter signature is written only once at the beginning of the score. They key signature determines the key of the work. The circle of fifths is where the sharp keys appear around the right side, while the flat keys appear around the left side as shown in the example below:
The key signature goes between the clef and meter signature - clef, key, meter - alphabetical order. To find the key of a piece, first check the key signature, then check the beginning and end of the piece for characteristic scale degrees.
the major pentatonic scale
Featuring only five of the seven diatonic pitches is called pentatonic. Of the numerous pentatonic collections found in folk and popular music, there's major pentatonic because it begins wih the first three degrees of the major scale.