While the rootless II-V-I concept introduced in Part 1 is an excellent starting point and “go-to” option for major II-V-I’s in most cases. It is common to occasionally “alter” the V chord in a major II-V-I in cases where it does not interfere with the melody. In some cases, the altered V chord is the preferred sound and will support a melody better than the strictly diatonic II-V-I pattern introduced in Part 1.
The simplest and most straightforward way to get this sound into your playing is by using the dominant 7th(b9) voicing from Part 2 as the V chord in your existing major II-V-I pattern. There is a bit more movement involved from chord to chord, but the result is smooth and works well.
There are many, many options when it comes to voicing and interpreting a II-V-I progression. This technique is useful in many situations, but not all. Pay close attention to the notes of the melody and listen for any clashing before settling on a voicing for a particular section of a tune.
For example, the second measure of “Autumn Leaves” has a V chord on F7. The melody of the tune plays F - G - A, which includes the natural 9th of the F chord. In this case, the F7(b9) might clash with the melody of the tunecould sound better with the rootless voicing from Part 1, which contains the natural 9th of the V chord.
Every tune will offer its own opportunities for choosing creative voicings and interpreting the harmony. Also keep in mind that the voicings played during the melody do not have to match the voicings played during solos. The solo sections have a lot more freedom and opportunity for experimentation in most cases.