

Shepard tone - mekoka
http://en.wikipedia.org/wiki/Shepard_tone

======
JonnieCache
It's also possible to make such a thing as a shepard rhythm, using much the
same principles. It's a lot harder though. Here's an excellent example:
<http://stretta.bandcamp.com/track/as-clean-as-fire>

I highly reccommend listening to and purchasing the whole album if you like
bach style soothing-yet-maths-based music.

~~~
cpa
That's pretty cool! Is there an analysis of this song (or album) somewhere?

~~~
JonnieCache
There's this blurb he wrote on the soundcloud page:

 _"When I see a photo of a modular synthesizer, I wonder, as I think many
others do, what the thing sounds like. What possibilities lurk within this
strange hardware? I want to hear something orchestrated and controlled. I want
to hear someone commanding the instrument with authority, not merely floating
on waves of serendipity. I want to hear something composed for the instrument,
leveraging its strengths, not a orchestration of an existing composition.

'A Funneled Stone' is a pure modular synth release, tracked the old-shool,
1970's way: one monophonic line at a time. Every sound you hear was created,
patched and recorded for that moment in time. When a new sound is needed, the
patch is torn down and a new one is built. Polyphony is achieved by tracking
each voice individually.

A modular album is, by definition, unapologetically synthetic. I also tried to
take a more minimalist approach to orchestration, so the individual sounds can
be more fully isolated and appreciated. I spent much of the final month of
production taking elements out, and editing for length. Sometimes this results
in the remaining elements merely hinting at the underlying harmonic movement.

As you can imagine, this process is very time-consuming, but fun. I hope you
enjoy the results as much as I enjoyed creating it."_

For more super-hi-tech-math-music have a listen to this:
[http://detroitunderground.net/blog/2012/05/03/vaetxh-
libet-t...](http://detroitunderground.net/blog/2012/05/03/vaetxh-libet-tones-
du17/)

That page has technical descriptions of what's happening in each track. Risset
illusions are just the start of the psychoacoustic trickery which goes on in
that record.

A word of warning however: unlike the stretta stuff, the Vaetxh tracks are
_REALLY NOT SOOTHING._ If you are soothed by them, seek help.

------
SideburnsOfDoom
Hm, to me it sounds like a sequence of overlapping falling tones. There's a
noticeable point where the falling tone is supplemented by one above it. This
first happens about 20s in.

 _edit_ The noticeable change seems to be very close to 22s.

~~~
mojuba
It does sound like an auditory illusion to many, as not everyone can isolate
tones in a mixed sound.

I'm curious if you happen to be a musician or a sound engineer?

~~~
SideburnsOfDoom
Nope, I'm not a musician or sound guy. I'm a coder. But I do enjoy music.

That falling tone on the Wikipedia page sounds like something from one of
_coil_ 's tracks. I can't pinpoint which one though? they use similar sounds
here <http://www.youtube.com/watch?v=c6IR90tgtDI> and here
<http://www.youtube.com/watch?v=9_R-mXRONh0>

_edit_ Expectation may pay a part - when told "come and listen to this
'endlessly falling' auditory illusion" of course I'm going to try and pick out
the subtle seams. I might not notice if it was in the background, unannounced.

------
robert-boehnke
This effect was also used for the infinite stairs in Super Mario 64

[http://www.youtube.com/watch?feature=player_detailpage&v...](http://www.youtube.com/watch?feature=player_detailpage&v=70J8SOX5w64#t=30s)

~~~
Surio
Yes! until the batpod replaced it from collective consciousness. Thanks for
the memories!

------
robot
Sounds like gödel, escher, bach
<http://en.wikipedia.org/wiki/G%C3%B6del,_Escher,_Bach>

~~~
tgb
These are mentioned at least once in GEB.

------
jftuga
Águas de Março is a famous Brazilian song by Antonio Carlos Jobim that employs
Shepard tones. It is very easy to hear the use of the technique in the song:
<http://www.youtube.com/watch?v=srfP2JlH6ls>

From Wikipedia: <http://en.wikipedia.org/wiki/Waters_of_March>

The inspiration for "Águas de Março" comes from Rio de Janeiro's rainiest
month. March is typically marked by sudden storms with heavy rains and strong
winds that cause flooding in many places around the city. The lyrics and the
music have a constant downward progression much like the water torrent from
those rains flowing in the gutters, which typically would carry sticks,
stones, bits of glass, and almost everything and anything. The orchestration
creates the illusion of the constant descending of notes much like Shepard
tones.

------
fictorial
I hear a loop ~22 seconds long of a falling tone. I can clearly hear the
higher pitch tone fade in at the start of each cycle. I'm not such I get the
"gets no higher or lower".

I'm listening to this version: <http://www.youtube.com/watch?v=DfJa3IC1txI>

------
10dpd
Why is this the top HN story? There are tons of perceptual audio examples that
have been around for decades. Check out Curtis Road's Computer Music book for
an in-depth analysis of this technique and more.

~~~
charliesome
Because it's cool and hackers like cool things. I would never have known about
this if it didn't make it to the top of HN.

~~~
10dpd
So can we come up with an meaningful definition of 'cool'? There is an
infinite number of arbitrary 'cool' things in the world - audio perception is
definitely interesting, but so is granular synthesis, binaural audio and
physical modelling.

I'm just not sure if the role of HN is to educate users on 'cool' things.
Maybe its because most of the US is currently sleeping...

~~~
charliesome
_On-Topic: Anything that good hackers would find interesting. That includes
more than hacking and startups. If you had to reduce it to a sentence, the
answer might be: anything that gratifies one's intellectual curiosity._

<http://ycombinator.com/newsguidelines.html>

------
VMG
Cool find. It says that it can be interpreted either as a rising or a falling
tone, but I only can hear a falling one, even if I try to interpret it as
rising.

~~~
Jabbles
Each tone is either rising or falling. This example is falling.

------
cbr
You can also use this illusion to make 'octveless notes':
<http://www.jefftk.com/octaveless/>

