Note: If you’re not a jazz pianist/instrumentalist or jazz composer/arranger, this post might not be of much interest, but it’s a question I’ve wondered about for many years.
There are two jazz piano voicings (closely related) known colloquially as “Locked Hands” and “Drop-2” voicings. In Locked Hands (often also referred to as the “Shearing Sound” after George Shearing who pioneered the technique), the right hand plays a melody with the 4th and 5th fingers (while the remaining fingers play other pitches in the chord) and the left hand doubles the single-note right hand melody an octave below. In Drop-2, the right hand does the same as in Locked Hands, but leaves out the pitch under the melody, which is played by the left hand, effectively creating a melody harmonized in 10ths. Both voicings are found in 19C piano music (Beethoven and others) so these were not invented by jazz musicians, but they were assimilated and adapted, and turned into something much more than a coloristic effect or flavor.
Here are a few examples from YouTube so you can hear what this sounds like:
1. Locked Hands This is George Shearing talking to Billy Taylor and Marian McPhartland. Shearing demonstrates Locked Hands at 1:16 (at speed), and then plays some simple examples very slowly at 2:50.
2. Drop-2 This is Bill Evans playing “How Deep is the Ocean?” and the melody uses a lot of Drop-2 (starting at 1:14).
Pianists today use drop-2 as chordal accompaniment and in solo piano to some degree, but locked hands is hard to find at all. Also, I don’t know of anyone (other than some period specialists) who actually improvises using either Locked Hands or Drop-2. I can understand why–improvising with them is really hard to do! I still marvel at the fluidity and ease that players like Evans and Shearing demonstrate so often in their many recordings. I worked on soloing using Locked Hands and I use it occasionally (I tried with Drop-2, but never made much headway in terms of improvising with it). I love the sound, but I’ve always wondered why I don’t hear it more–is it too dated and out-moded for anything other than period pieces?
There must be some interest in it because well-known jazz educator Mark Levine recently released an excellent method book on Locked Hands and Drop-2 voicings, but they don’t appear very much in modern usage. Perhaps then, they have become in jazz what they were in classical music–an occasional foreground melodic voicing, but more often than not, a background color, providing relief and variety to the texture.