In music theory

Music theory

Music theory is the study of how music works. It examines the language and notation of music. It seeks to identify patterns and structures in composers' techniques across or within genres, styles, or historical periods...

, the dominant parallel is terminology used in German theory (Functional harmony

Diatonic function

In tonal music theory, a diatonic function is the specific, recognized role of each of the 7 notes and their chords in relation to the diatonic key...

) derived mainly from Hugo Riemann

Hugo Riemann

Karl Wilhelm Julius Hugo Riemann was a German music theorist.-Biography:Riemann was born at Grossmehlra, Schwarzburg-Sondershausen. He was educated in theory by Frankenberger, studied the piano with Barthel and Ratzenberger, studied law, and finally philosophy and history at Berlin and Tübingen...

. The dominant parallel is abbreviated Dp, in major

Major and minor

In Western music, the adjectives major and minor can describe a musical composition, movement, section, scale, key, chord, or interval.Major and minor are frequently referred to in the titles of classical compositions, especially in reference to the key of a piece.-Intervals and chords:With regard...

, and dP, in minor, where a capital letter (e.g. "D") denotes a major chord

Major chord

In music theory, a major chord is a chord having a root, a major third, and a perfect fifth. When a chord has these three notes alone, it is called a major triad...

 (the dominant) and a lowercase letter (e.g. "p") denotes a minor chord

Minor chord

In music theory, a minor chord is a chord having a root, a minor third, and a perfect fifth.When a chord has these three notes alone, it is called a minor triad....

 (its parallel). It is the (US) relative

Relative key

In music, relative keys are the major and minor scales that have the same key signatures. A major and minor scale sharing the same key signature are said to be in a relative relationship...

 to the dominant

Dominant (music)

In music, the dominant is the fifth scale degree of the diatonic scale, called "dominant" because it is next in importance to the tonic,and a dominant chord is any chord built upon that pitch, using the notes of the same diatonic scale...

 and is thus considered to have or fulfill the function of the dominant.
The parallel chord

Chord (music)

A chord in music is any harmonic set of two–three or more notes that is heard as if sounding simultaneously. These need not actually be played together: arpeggios and broken chords may for many practical and theoretical purposes be understood as chords...

 (but not the counter parallel

Counter parallel

In music theory, the counter parallel is terminology used in German theory derived mainly from Hugo Riemann to refer to relative diatonic functions and is abbreviated Tcp in major and tCp in minor...

 chord) of a major chord will always be the minor chord whose root

Root (chord)

In music theory, the root of a chord is the note or pitch upon which a triadic chord is built. For example, the root of the major triad C-E-G is C....

 is a minor third

Minor third

In classical music from Western culture, a third is a musical interval encompassing three staff positions , and the minor third is one of two commonly occurring thirds. The minor quality specification identifies it as being the smallest of the two: the minor third spans three semitones, the major...

 down from the major chord's root, inversely the parallel chord of a minor chord will be the major chord whose root is a minor third up from the root of the minor chord. Thus, in a major key

Key (music)

In music theory, the term key is used in many different and sometimes contradictory ways. A common use is to speak of music as being "in" a specific key, such as in the key of C major or in the key of F-sharp. Sometimes the terms "major" or "minor" are appended, as in the key of A minor or in the...

, where the dominant is a major chord, the dominant parallel will be the minor chord a minor third below the dominant. In a minor key, where the dominant may be a minor chord, the dominant parallel will be the major chord a minor third above the (minor) dominant.
In C major:

• Dp is E minor, US mediant
  Mediant
  In music, the mediant is the third scale degree of the diatonic scale, being the note halfway between the tonic and the dominant. Similarly, the submediant is halfway between the tonic and subdominant...
  
  

In C minor:

• dP is B major, US subtonic
  Subtonic
  In music, the subtonic or flattened seventh is the lowered or minor seventh degree of the scale, a whole step below the tonic, as opposed to the leading tone...