Rootless voicings can either be formed as left hand close voicings or two handed open voicings. Left hand close rootless voicings are used to accompany yourself while either soloing or playing the melody in your right hand. The two handed open voicings are used to comp background chords while accompanying a soloist (usually in full group playing that includes a bass player). Coming back to the concepts of shell voicings and guide tones, we remember that the 3rd and the 7th are the most important intervals in major 7th, minor 7th and dominant 7th chords (beside the root). Since all of these chords contain a perfect 5th, the 3rd and 7th help to define the quality and color of the chord.
Rootless voicings are derived from using either the 3rd or 7th of the chord as a starting point. We will start by discussing the left handed close voicings, and then expand to the two handed open voicings. They can be played in either an A or B form. The A form is created by starting with the 3rd of the chord and stacking the other intervals above it in a close voicing. The B form is created by starting with the 7th of the chord and stacking the other intervals above it in a close voicing. The reason for the two forms of voicing is to help maintain an appropriate register on the keyboard while performing. Voicing the chord too low will cause it to sound muddy, and voicing it too high will encroach on the playing of the right hand. Musicians use their ear and common sense to regulate this. For those who have trouble distinguishing the proper range, a good general rule is to try to keep your left hand pinky between middle C and the C one octave below middle.
When voicing major, minor and dominant seventh chords, the fourth pitch usually used (since the root is not present) is the ninth. In addition, when voicing dominant seventh chords the 13th is often used to replace the fifth. This allows for better voice leading especially in II-V-I progressions.
This Learning Music With Ray video discusses rootless piano chord voicings both in a close left hand voicing and a two hand open chord voicing. In the video, I explain why piano players would want to voice their chords without a root. I provide visual examples of major, minor and dominant seventh chords written on a musical staff in both close left hand and open two hand voicings. I explain the strategies for obtaining these voicings, and how they can be applied to the II-V-I chord progression. Finally, I demonstrate all of these examples on the piano keyboard.