Seventh chord an augmented fifth, and an augmented seventh (i.e., a sequence of 3 major thirds, such as C–E–G–B), is a rarely used tertian seventh chord. The reason is that the augmented seventh interval is enharmonically equivalent to one entire octave (in equal temperament, 3 major thirds = 12 semitones = 1 octave) and is hence perfectly consonant with the chord root. The seven commonly used chords are: Seventh chords can also be constructed using augmented or diminished thirds. These chords are not tertian and can be used in non-tertian harmony. There are many (mathematically, 64) chords that can be built, however,
Octave (liturgy) Season make up the octave of Easter and are celebrated as solemnities of the Lord, with proper readings and prayers. Since 30 April 2000, the "Second Sunday of Easter", which concludes the Easter Octave, has also been called Divine Mercy Sunday. The Christmas Octave is arranged as follows: Among the Eastern Orthodox and Byzantine Rite Eastern Catholic Churches, what in the West would be called an Octave is referred to as an Afterfeast. The celebration of the Great Feasts of the church year are extended for a number days, depending upon the particular Feast. Each day of an Afterfeast will