A Jump Ahead does not have a conventional melody or theme.
Instead, the tune gets its structure from a four-bar ostinato played by bassist Paul Chambers.
An ostinato is a short melody pattern that is constantly repeated in the same part at the same pitch.
Nat Hentoff’s notes contain this further elabaoration:
“The rule which Hancock set for A Jump Ahead was for Paul Chambers to select an introductory four-bar pedal tone. ‘Then there come sixteen bars of time,’ Hancock points out, ‘in which what I improvise is based on the pedal tone Paul played during the first four bars. Another four-bar break follows, for which Paul selects another note. I never knew what Paul would play, and that's how this one got titled. He was always a jump ahead. Incidentally, since any one note can be related to all twelve tones on the keyboard, I had complete freedom to utilize Paul's pedal notes any way I wanted to. Those notes acted as a note in a chord, but I formed the chords in my own way. Again, there was no preconceived melody, and the harmony came from the notes Paul chose.’”
Structurally, A Jump Ahead is what may be referred to as tonal music.
And in tonal music, a pedal tone is a sustained tone, played typically in the bass. Sometimes called a pedal point, a pedal tone is a non-chord tone.
The term “pedal tone” comes from the organ’s ability to sustain a note indefinitely using the pedal keyboard which is played by the feet; as such, the organist can hold down a pedal point for lengthy periods while both hands perform higher-register music on the manual keyboards.
In effect, Chambers acts like the organ pedal keyboard while Herbie plays over it using both hands on the piano keyboard.
One other point that may be of interest is Willie Bobo’s use of very thick/heavy drumsticks that really serve to crackle & pop the snare drum and crash the cymbals. Such large sticks take great control and using them masterfully,Willie generates tremendous swing on this six-and-a-half minute cut.
Paul’s four-bar ostinato can be heard at the outset of the track, again at 18 seconds, and again at 35 and 53 seconds and so on.
Each time it is followed by a 16-bar improvisation that Herbie conceives based on the pedal tone that Paul selects.
In effect, A Jump Ahead is the Jazz equivalent of the geometric head-start in which one never catches-up.
To my ears, Herbie’s solo really hits its stride on A Jump Ahead at around the mark [which Willie conveniently underscores with a cymbal crash!] and just soars thereafter.
See what you think.