The diminished seventh chord is very versatile and can be used in many musical situations. I covered the two basic diminished chord progressions (I6, Idim, IIm7, V7; and I6, I#dim, IIm7, V7) and their use in introductions, modulations, fills, repeats of themes (turnarounds), and interludes in my study book Diminished Chord Magic (Hal Leonard Publishing). However, there has been a great deal of interest in the diminished scales which can be used with the corresponding diminished chords, to provide fills and melodic ideas for improvisation.
First, remember the magic formula: There are actually only three different diminished chords. Each diminished chord, itself, contains four diminished chords because each note in a diminished chord is the name (root) of a diminished chord. Study the illustrations:
Simply associate the three diminished chords with the three simplest keys. Since any inversion of a chord is equal to any other inversion, the diminished chords are correct played in any inversion/position. The root played in the bass will determine the name given to the diminished chord.
Next, study and practice the diminished scales associated with each set of diminished chords:
To extend the diminished scales beyond one octave, use the 1st finger of the right hand to play the octave note.
Using a variety of rhythm accompaniments (for example, sustain the diminished chord with the left hand and pedal four beats to the measure; or play four left-hand chords per measure, one on each beat, while pedaling on the first and third beats), practice the diminished scales using different note values. Suggestions:
Before adapting the diminished scales for your own use, study, practice, and perform the following two examples of how the scales can be used to create melodic improvisation lines:
Here is one way I’ve used the chromatic augmented chords in a four-measure break in a jazz blues (play the indicated chord on the downbeat and then rest for seven beats):
If you made a resolution to read more books about music this year, I have a couple of suggestions. American Popular Song, by Alec Wilder (Oxford University Press), is described by its publisher as “... the first authoritative, fully analytical study of the development of American popular song.”
A tremendously valuable set of books in the field of composition and melodic improvisation is The Polytonal Rhythm Series, by Emile De Cosmo, which, its publisher states, “... may be used in conjunction with any method. Its purpose is to give to the student a systematic approach to the development of melodic motifs which in turn become musical phrases. An aid in the development of the ear.”
Finally, there is a 672-page masterpiece for the serious musician, compiled under the direction of Genichi Kawakami, President of the Yamaha Music Foundation, entitled Arranging Popular Music: A Practical Guide. The book is written both in English and in Spanish, and is profusely illustrated. Although all instruments are pictured, explained, and developed in orchestration, the organist (whose playing, theoretically, should be “orchestrated”) will find a tremendous range and amount of material on all fields of modern music. The table of contents alone is eleven pages long and includes many too many subjects to list here, but under Chords alone there is Basic Harmonizing Theory, Chord Types, Basic Chord Progression and Their Variations, Chord Patterns, Chord Progressions and Bass Lines, Special Chord Progressions, Gregorian Modes, Harmonization, Jazz Harmonization, Pedal Point, Modulation, and Partial Modulation—and I haven’t even included the subtitles!
In a characteristically modest statement, President Kawakami’s Foreword states, “While we can pride ourselves on the fact that this is apparently the world’s first attempt to present materials for the systematic study of popular music, the present work is no doubt imperfect in many points, but subsequent printings will hopefully incorporate improvements.”
[Although it has been 40 years since the author suggested these titles, they continue to be excellent materials for the serious music student and worth looking for, either in a library or an online bookstore. —Ed.]