Practicing contrapuntal music

Playing bebop lines in octaves

Switching roles between the left and right hands in improvisation

Typically, when it comes to jazz piano, it’s fair to say that melodic lines tend to be played in the right hand, accompanied by chords (2-, 3-, or 4-note voicings) in the left. However, turning this familiar situation around (i.e. reversing the parts played by each hand) on a regular basis when practicing/performing proves to be highly beneficial: a strong left hand is an important feature, adding variety of range and texture. Incorporating this technique into your palette will have the following effects:

• stronger hand independence will be achieved, both rhythmically and harmonically: playing notes other than roots and fifths (and other common chord tones/approaches typically played in bass lines), notably tensions as part of the melody in the low end against the chords higher up in the mid register, can be a novel experience and will have the effect of stretching the realm of what is commonly heard by the ear and processed by the mind.
• it might lead you to use different voicings than the ones you usually use for comping. Sometimes a voicing might be too low and sound muddy when played with the left hand in the lower part of the keyboard, but the same voicing played higher up will sound OK due to the absence of low interval limit restrictions;
• the left hand is generally weaker and slower than the right hand. Such technical restriction forces you to rely more on musicality, inner hearing and singing when improvising with the left hand. When you then go back to improvising with the right hand, it feels a lot easier! Musicality is now right at your fingertips, with the greater technical ability of your strong hand available to serve it.