Plagal meaning music

plagal. / (ˈpleɪɡəl) / adjective. (of a cadence) progressing from the subdominant to the tonic chord, as in the Amen of a hymn. (of a mode) commencing upon the dominant of an authentic mode, but sharing the same final as the authentic mode.

1. What is the meaning of plagal?
2. Why is it called plagal?
3. What is plagal extension?
4. What is a plagal cadence chord?

What is the meaning of plagal?

1 of a church mode : having the keynote on the fourth scale step — compare authentic sense 4a. 2 of a cadence : progressing from the subdominant chord to the tonic — compare authentic sense 4b.

Why is it called plagal?

A plagal mode (from Greek πλάγιος 'oblique, sideways, athwart') has a range that includes the octave from the fourth below the final to the fifth above. ... In Byzantine modal theory (octoechos), the word "plagal" ("plagios") refers to the four lower-lying echoi, or modes.

What is plagal extension?

Plagal motion [(IV)-I] serves to prolong tonic either after an AC or at the beginning of a phrase. We place plagal (IV) in parentheses in analysis to differentiate it from the more common use of IV as a predominant. ... Plagal motion more commonly occurs as part of a prolongation rather than as part of a cadence.

What is a plagal cadence chord?

[English] A chord progression where the subdominant chord is followed by the tonic chord (IV-I). The "IV" represents the chord based on the fourth step of the scale and the "I" represents the chord based on the first step of the scale.