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 Chanute Octave Chanute Octave Chanute (February 18, 1832, Paris – November 23, 1910, Chicago, Illinois) was an American civil engineer and aviation pioneer, born in France. He provided many budding enthusiasts, including the Wright brothers, with help and advice, and helped to publicize their flying experiments. At his death he was hailed as the father of aviation and the heavier-than-air flying machine. Octave Chanute was the son of Elise and Joseph Chanut, professor at the Collège de France. He emigrated with his father to the United States of America in 1838, when the former was named Vice-President at Jefferson College in