CHORDS IN THE LIGHT OF THEIR ORIGIN 



reports the components of its nucleus-triad to be 1, 3, 5 

 of I and reports its added tone to be 3 of IV, while in 

 b) the chord / + 2 reports the components of its 

 nucleus-triad to be i, 3, s of / and reports its added 

 tone to be 5 of ///. Thus neither of the two chords 

 contains and reports a harmonic seventh. Hence this 

 obvious question: Should chords without harmonic 

 sevenths be known and classed as seventh-chords? 

 Thorough-bass answers yes; harmony answers no. 

 That is to say, from the view-point of thorough-bass 

 the above chords are seventh-chords, from the view- 

 point of harmony they are not. If we distinguish 

 between the two view-points, both of which are neces- 

 sary, there need be no difficulty or confusion. In fact, 

 the prevalent thorough-bass system and its termi- 

 nology are indispensable to the theory and practice of 

 harmony; not only is their utility unquestionable, but 

 they have become fixed habits. The adoption of a 

 simple and exact term from the German will, I think, 

 remove the whole difficulty. To explain: For triad 

 the German says Dreiklang, for seventh-chord the 

 German says not only Septimenaccord, but also Vier- 

 klang. Vierklang is the term in question. According 

 as we may prefer its Latin or Greek derivation the 

 English equivalent of Vierklang is quadrad or tetrad. 

 I suggest the adoption of the term tetrad as the class- 

 name of all chords of four components. Tetrads may 

 be subdivided into as many distinct groups as there 

 are distinct structures. Thus seventh-chords would 

 form one group, supersixth-chords would form another 

 group, subsecond-chords still another, and so on. 

 Such a classification would not only conform both 



