Chord-Tone vs. Chord-Scale Soloing
For the past few decades or so, more and more jazz players have been using the chord-scale approach for soloing over chords in progressions. The chord-scale approach is based on the idea that if a chord is diatonic to a scale, then that scale can be used as a source to derive melody on that chord.
Using the chord-scale approach gives improvisers (especially less proficient ones) greater melodic and rhythmic mobility (i.e., they can improvise pitch sequences in eighth notes, triplets, sixteenth notes, etc.). Whereas chord tones must be played in leaps (minor third intervals or wider), a chord scale can be played in steps (major and minor second intervals), and consecutive steps are much easier to play fast and accurately than consecutive leaps. In general, less-experienced players are also familiar with scales and scale patterns than chord arpeggios from practicing technical exercises in method books and, therefore, prefer to use chord scales for improvising.
A chord scale contains not only the tones of the chord to which it is applied, but also the tensions. Therefore, by improvising on a chord using a chord scale, the soloist will almost certainly play some chord tones and some of the more colorful notes (tensions) as well. It is likely that without the help of chord scales, a soloist may not know (i.e., be able to hear) specifically what tensions fit the chord tones appropriately in a particular harmonic context.
So, in a sense, chord scales do the work of and for the ear. They enable an improviser to play active melody lines that not only agree with the chords, but also contain the more colorful melody notes (i.e., notes other than chord tones) that the player may not be able to find or select by ear alone.
However, for beginner and intermediate-level players, the chord-scale approach has a potential downside. Many students begin studying chord scales early in their musical education and attempt to apply the knowledge acquired immediately on their instruments. Unfortunately, this often happens too soon in the student's development as an improviser--before he or she has learned how to shape an appealing improvised melody by ear on a chord or chord progression using only, or mainly, chord tones.
Chord scales can present too much information, or information that cannot be readily processed, controlled, and used musically by the novice improviser. It is much easier to understand chord-scale theory than it is to apply it with musical results in an improvised solo. Improvising on chords with chord scales means that a soloist can play melody notes that he or she does not recognize or cannot identify and control by ear. This can result in wandering, shapeless, directionless, or mechanical-sounding melody lines. Often the lines are played in eighth notes to the exclusion of all other rhythm values, producing undesirable melodic and rhythmic content. Such improvised melodies often tend to outline tonic quality on nontonic functioning chords and vice versa.
Direction changes in the melodic curve are also somewhat less frequent because the rhythms are predominantly eighth notes and are less noticeable because of the predominance of stepwise motion. (Melodic intervals wider than a second or a third are less common if not rare in elementary-level improvised solos using the chord-scale approach.) This produces a consistently linear melodic line that sounds limited or uninteresting because it is not balanced by more angular melodic curves.
It is relevant to point out here that the pioneers of jazz improvisation relied on their listening/hearing skills and their ability to accurately outline basic chord sound to guide their improvising and to create inspired melodies. They did not rely on the mechanics of chord scales. Beginning improvisers should, therefore, first experience how good it sounds and how right it feels to play inside the chords using only the chord tones before experiencing the allure and sophistication of chord scales. Improvising melodies using only chord tones connects the soloist to the song's harmony, giving him or her a feeling of oneness with the music. This is essential before a player can hear how to use chord scales and nonharmonic approach notes effectively.
Ideally, melodic ear training for improvisers should begin with chord-tone soloing and then advance to chord tones with approach notes and/or chord scale soloing. The musical example is a chord-tone solo on the progression of a well-known standard tune.
Is Chord-Tone Soloing Necessary for Advanced Improvisers?
I recommend that advanced improvisers take the following chord-tone soloing test to determine for themselves whether or not they are ready to use the chord-scale approach on a particular tune's progression.
1. Write out the chord progression of a familiar song on manuscript paper. Put the chord symbols above the staff and write out the chord tones in root position on the staff to observe while soloing.
2. Record yourself playing an unaccompanied four- to six-chorus improvised solo at a medium tempo on the chord progression using only chord tones. Try to use all or most of the chord tones of each chord you play on. Include rhythmic variety, syncopation, varied phrase lengths, pacing, dynamics, etc.
3. Transcribe your improvised solo and analyze the function of each melody note as it relates to each chord, being careful to note harmonic anticipations whenever they occur. Write the melody/harmony relationship on the transcription under each melody note.
If your improvised melody is more than 90 percent accurate (e.g., your melody contains nearly all of the chord tones of each chord you played on), it is safe to assume that you are ready to practice improvising on the progression using chord scales. Or, if you prefer, change the tempo and/or the key and repeat the test.
If your improvised melody is less than 90 percent accurate (as is often the case, even with advanced players), it is reasonable to assume that you will benefit from practicing chord-tone soloing on the song's harmony.
These steps outline an effective way to practice chord-tone soloing on a chord progression.
1. Practice playing arpeggio patterns in eighth notes and triplets for several minutes on each chord in a progression to become familiar with the chord tones on your instrument.
2. Improvise on each chord of the progression individually (one chord at a time, modal style), for several minutes while incorporating the arpeggio patterns and using only chord tones. You can also use a one- or two-measure rhythmic motif, such as:
That will help you to focus less attention on rhythm and more on melodic accuracy, melodic curve, etc.
3. Improvise on two- or three-chord groupings from the tune's progression while observing the original harmonic rhythm, using only chord tones, with and without a rhythmic motif. Chord-tone soloing is a great way to improve your level of proficiency with any song's harmony. By practicing chord-tone soloing before you work on chord-scale soloing, you'll be building your musical house from the floor up rather than from the roof down. Happy hammering!