For all of the similarities that exist between the two, rock piano-playing and jazz piano-playing also have many obvious differences. One big difference in terms of technique has to do with the use of the left hand. In a jazz setting, the pianist’s left hand is often used for comping (i.e., playing chords in a rhythmically varied style of accompaniment). These left hand chord voicings frequently do not include the root of the chord since playing the root is generally reserved for the bass player (unless the pianist is playing in a solo piano context). Also, these chords commonly include 7ths and other upper extensions, such as 9ths, 11ths, and 13ths. The rock pianist’s left hand, by contrast, sometimes plays chords but more frequently plays only the roots of the chords often in octaves and sometimes including the 5th of the chord. Also, instead of trying to “stay out of the way” of the bass player (as many jazz pianists often suggest), the rock player’s left hand is commonly doubling what the bass player might be playing.

In this article we will look at 3 examples of some common left-hand devices of the rock piano player and discuss how it is different and similar to the left hand of the jazz pianist.

EXAMPLE 1: The Blues

A jazz pianist’s left hand generally plays what are referred to as close-position rootless voicings (i.e., chords that are within an octave range and generally contain chord tones and upper extensions, often without the root present in the chord). The right hand can act as an extension of the left hand in order to create a large chord voicing, or can choose to solo/improvise while the left hand continues to play the close-position voicings. The left hand comps rhythmically, but the jazz player is free to create rhythmic variations in his comping in order to create syncopations and interact with the other rhythm sections players (i.e., bass and drums).

By contrast, a rock player’s left hand often reinforces what is being played by the bass player by playing roots or even a specific groove in the bass register of the piano, thereby creating a thicker, denser bass part that locks in with the rhythmic groove of the drums, as opposed to adding syncopated rhythms in collaboration with the drums (such as in the jazz swing feel). The rock player’s right hand generally plays a repetitive rhythmic and chordal figure that locks in with the left hand part.

EXAMPLE 2: Leadsheet/Fakebook Example

Look at the simple 4 measure phrase below.

A traditional jazz piano approach to playing this phrase might be to play the melody as a single-note line in the right hand while the left hand comps using close-position rootless voicings.

Alternatively, the rock pianist’s approach might involve playing the roots of the chords in octaves in the bass register with the left hand, while the right hand harmonizes the melody using a simple triadic approach.

EXAMPLE 3: Jazz Standard vs. Rock Tune

Generally speaking, a jazz pianist will rarely double the exact same bass line as the bass player. Of course, there are times when this is not the case. However, even in those instances when the pianist and bass player are playing the same bassline this usually only lasts for a portion of the song and is scripted, and the jazz pianist’s left hand eventually returns to comping figures. The nature of jazz and its emphasis on the improvisational component allows the pianist and bass player to be inventive, meaning that the bass player’s bass lines and the pianist’s chord voicings are not pre-determined but instead are created spontaneously.

By contrast, there are many pop/rock/funk tunes in which the keyboardist’s left hand plays exactly the same thing as the bass player (referred to as “doubling” the bass line). This will oftentimes continue throughout the entire tune.