6-4 · Same Sequence, New Starting Point: Beat Displacement

In the last lesson we noticed, almost by accident, that groups of three in sixteenth notes don't stay put — each group starts on a different part of the beat. This lesson makes that the whole point. Where a sequence sits against the beat is another powerful variable, and most of us never think about it, because we all default to starting right on the beat.

One piece of vocabulary first. In 4/4 time, your ear doesn't treat all four beats equally, and whatever lands on the strong beats is what it picks out as the skeleton of the line.

Choosing the starting point

Start with a sequence that behaves itself: groups of four in eighth notes. Four notes fill two beats exactly, so every group starts in the same place against the pulse with no rotation to worry about yet. Here it is starting on beat one, the way you'd play it without thinking:

Play the exact same thing starting on beat 2, and every pitch is the same, but a different note in each group is landing on the strong beats — your ear picks out a different skeleton. It's a different melody made of the same notes.

Now start on the "and" of 1:

The whole line sits off the beat and gets a floating, pushed-ahead feel, and it ends up emphasizing the last note in each group, because that's the note that always lands on a strong beat. With the same pitches and same rhythm, we can get three different-sounding lines, just from moving the starting point.

Letting the pattern and the pulse disagree

Now the fun part. Go back to groups of three in straight sixteenths and watch the start of each group: on the beat, then the "a," then the "and," then the "e." The accent walks around the pulse.

Musicians call this metric displacement, or "three against four": the pattern is three notes long, the beat is four sixteenths long, and since four doesn't divide evenly by three, the pattern keeps landing somewhere new. The pitches repeat, but the accents change, so your ear keeps hearing something slightly different. Remember the staleness clock from 6-1, three or four times through before a sequence goes stale? Displacement extends that clock. The line floats free of the beat for a while, and when it finally lands back where it started, you get that satisfying coming-home feeling — tension and release, built right into the sequence.

You can work out how long the float lasts for any combination of sequence length and meter. The rotation happens whenever the group length and the beat length don't share a common factor. Three against four takes twelve notes to come home. The same groups of three in eighths is three against two, which comes home after six notes — three beats. A five-note figure in eighths is five against two: ten notes, five beats. In sixteenths, five against four takes twenty notes. The bigger the mismatch, the longer the line floats before it resolves.

Fair warning: these combinations can be genuinely hard to hear at first. You'll lose the beat, and the pattern will try to drag your foot along with it. That's normal, and it's a skill we need to train. Anchor the pulse by tapping your foot, or better, keep a metronome or drum loop running, and always know where beat 1 is. Then let the sequence float over it. After a while, something nice happens: you will start to feel three against two or three against four as its own thing, and you won't have to think about it. The Melodic Sequence tool helps here too: set up a sequence, pick the subdivision and starting point, and watch the displacement play out on the fretboard while you listen.

Exercise 6-3: Deliberate starting points. Take any sequence (groups of four are a good start) and play it with different offsets: on beat 1, on the "and" of 1, on beat 2, on the "and" of 2. Each time, notice which note lands on the next strong beat. That's the note your listener hears as important.

Exercise 6-4: Displacement. Play groups of three in steady sixteenths over a four-beat drum loop, and let it run until the accents cycle back to where they started. Then try starting on a different subdivision of the beat — starting on the "e" or the "a" feels wildly different than starting on the downbeat. Then pick a bigger mismatch, like a five-note figure, and try it in eighths, triplets, and sixteenths. Keep a drone under everything, count out loud when you need to, and go as slow as it takes.