
Shepard Tone - tintinnabula
https://en.wikipedia.org/wiki/Shepard_tone
======
smrq
Similar in concept is the Risset rhythm (it's briefly alluded to in the
article), where the tempo of the rhythm seems to constantly speed up or slow
down.

The song "Fold4, Wrap5" by Autechre is a cool example. It's not hard to see
how it works, but it's a delightful effect regardless. Each bar has a point at
which the beat shifts to a double-time version of itself, while the tempo of
the track constantly decreases so that the double-time rhythm transitions back
to the original rhythm.

~~~
lozaning
That song makes me really uncomfortable, like anxiety inducing. Neat! Always
cool to see how different music makes different people vibe certain ways.

Here's a youtube link if anyone else is interested:
[https://www.youtube.com/watch?v=SLvFsP1izS4](https://www.youtube.com/watch?v=SLvFsP1izS4)

~~~
fencepost
I can't imagine listening to that style as a regular thing, but I could easily
picture that as "alien music" for a movie or atmospheric background. Not
'musical' as I would think of it, but clearly recognizable as music for very
different ears or mental structures.

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jancsika
Here's a way to figure out how they work:

Listen to Bach's Fantasia from Fantasia and Fugue in G minor, BWV 542:

[https://www.youtube.com/watch?v=LWyiiOkhwoc](https://www.youtube.com/watch?v=LWyiiOkhwoc)

At about 3:54 you'll hear a famous section where Bach starts "circling" around
fifths. The general pattern is that the notes of the chords in the hands
"rise" while the feet descend.

Listen to the bass line. It seems to descend by step for thirty notes in a
row. But try singing _any_ note and singing down a scale for thirty notes in a
row. You probably can't do it. And if Bach did that in the bassline the final
note would be really low and flabby.

So how does the bassline seem to continue descending by step while remaining
in the same general range?

The answer is a two-word phrase that is usually met by profound boredom in
first-year music theory classes. But that concept is what Bach uses in the
pitch domain here to achieve his aim. And its analogous to what happens in the
frequency domain to produce a Shepard tone.

~~~
Excel_Wizard
I'm used to hearing the terms time domain and frequency domain. But I've never
heard pitch domain as a separate idea. Isn't pitch just the same as frequency?

~~~
n3k5
In this context, the term is just used to tell you to think in terms of pitch
_classes_ — where all notes that are separated by an integer multiple of an
octave belong to the same class — and not expect actual Shepard tone trickery
related to absolute pitch.

However, the relationship between absolute pitch and frequency isn't always
trivial. The latter is a physical phenomenon, but the former is psycho-
acoustic. When you have sounds with a normal set of overtones that align with
a harmonic series, the perceived pitch matches the fundamental frequency. But
that frequency doesn't actually need to be audible. By weighting the
amplitudes of the partials in a certain way, you can also construct a sound
that will be perceived as different pitches by different listeners, or by the
same listener under different circumstances.

With sounds whose frequencies aren't all harmonic, assigning a pitch can get
more complicated.

~~~
jancsika
> However, the relationship between absolute pitch and frequency isn't always
> trivial.

Not only is it not trivial, it is undefined. For example, "middle C" can map
to different frequencies depending on your tuning system, for just one
example.

Pitch is the higher level abstraction. Especially on the organ, "middle C" may
get interpreted as "middle C plus a C an octave below, plus another octave
below for good measure" depending on context. I assume that's what Carpenter
is changing when he's putting his hand on those pads where the stops should
be.

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dwrodri
There's a great example of Shepard Tones in Dunkirk:
[https://www.youtube.com/watch?v=LVWTQcZbLgY](https://www.youtube.com/watch?v=LVWTQcZbLgY)

~~~
kennywinker
Can’t watch the video atm, but in case it’s not mentioned - Nolan says he
based the structure of Dunkirk on the shepard tone. Always rising in
intensity, never ending. Great film!

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maleno
My favourite Shepard Tone example is Stephin Merritt's 'Project Song' video
for NPR [1]. It's also way more playful than most.

[https://youtu.be/OfFtEfxhMEQ](https://youtu.be/OfFtEfxhMEQ)

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vincent-toups
I feel like we're in a moment of cultural shepard tone - there is the sense
that we are barreling towards something and yet also the sense that nothing
can or is changing.

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OscarCunningham
What I'd like to see is the opposite effect: A keyboard where every note is
generated using only combinations of Cs, but with the weightings chosen so
that its average pitch is the one that that key usually has. This would have
the strange consequence that nothing you played would sound dissonant and any
piece you played would have the same affect as any other.

It would probably be boring to listen to all the time, but interesting to hear
it playing a piece which usually makes use of lots of dissonance.

~~~
yesenadam
This is not quite that, but does have a piece that had a lot of chord motion
converted to all C major:

(Coltrane's) _Giant Steps_ in C.
[https://www.youtube.com/watch?v=qTYzYpb1MY0](https://www.youtube.com/watch?v=qTYzYpb1MY0)

For jazz musicians it's very funny, in a horrifying kind of way, maybe listen
to the 1959 original first if you don't know it.
[https://www.youtube.com/watch?v=Lu0Lhysn_X8](https://www.youtube.com/watch?v=Lu0Lhysn_X8)

And thank you! While getting the links I found this wonderful animation of a
shortened version of the original:
[https://www.youtube.com/watch?v=rh6WTAHKYTc](https://www.youtube.com/watch?v=rh6WTAHKYTc)

p.s. Woohoo! Coltrane on HN! :-)

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1-6
Here's another one, built with Scratch.
[https://www.youtube.com/watch?v=Cx96CbjUZbA](https://www.youtube.com/watch?v=Cx96CbjUZbA)

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vagab0nd
My favorite demonstration of this has to be the engine sound of the Batpod:

[https://www.youtube.com/watch?v=_bpUSNZQAb4](https://www.youtube.com/watch?v=_bpUSNZQAb4)

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ashleyn
The first example of this I can remember was the endless stairs music from
Super Mario 64.

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piahoo
i think it is worth to mention glenn branca, he used this technique a lot.
good example is "The Tone Row That Ruled the World"

