adaptive string quartet

Hi All,

As you just read, Ive uploaded an adaptively tuned
"string quartet". Sorry about the double post,
but something very wierd happened when I was uploading
the first time.

The tuning in this piece slithers
around in such a way that at each instant the dissonance
is minimized. All the pitch sliding is done by the
algorithm. Since the "violins" are mostly harmonic,
most of the sustained intervals are just.

Bill Sethares

--- In MakeMicroMusic@y..., sethares@e... wrote:
>
> Hi All,
>
> As you just read, Ive uploaded an adaptively tuned
> "string quartet". Sorry about the double post,
> but something very wierd happened when I was uploading
> the first time.
>
> The tuning in this piece slithers
> around in such a way that at each instant the dissonance
> is minimized. All the pitch sliding is done by the
> algorithm. Since the "violins" are mostly harmonic,
> most of the sustained intervals are just.
>
> Bill Sethares

I wonder if you are aware that John deLaubenfels has been hard at
work on an adaptive tuning program for several years now:

http://www.adaptune.com/

He defines "pain" as a sum of contributions from vertical dissonance,
horizontal pitch shifts, overall pitch drift, and optionally other
factors. Then his program minimizes the total pain.

I'd be interested in comparing your approach with his . . . perhaps
the main tuning list would be the right place for that . . .

--- In MakeMicroMusic@y..., "Paul Erlich" <paul@s...> wrote:
> --- In MakeMicroMusic@y..., sethares@e... wrote:
> >
> > Hi All,
> >
> > As you just read, Ive uploaded an adaptively tuned
> > "string quartet". Sorry about the double post,
> > but something very wierd happened when I was uploading
> > the first time.
> >
> > The tuning in this piece slithers
> > around in such a way that at each instant the dissonance
> > is minimized. All the pitch sliding is done by the
> > algorithm. Since the "violins" are mostly harmonic,
> > most of the sustained intervals are just.
> >
> > Bill Sethares
>
> I wonder if you are aware that John deLaubenfels has been hard at
> work on an adaptive tuning program for several years now:
>
> http://www.adaptune.com/
>
> He defines "pain" as a sum of contributions from vertical dissonance,
> horizontal pitch shifts, overall pitch drift, and optionally other
> factors. Then his program minimizes the total pain.
>
> I'd be interested in comparing your approach with his . . . perhaps
> the main tuning list would be the right place for that . . .

sethares@e... wrote:
> >
> > Ive uploaded an adaptively tuned "string quartet".

paul e wrote:
>
> I wonder if you are aware that John deLaubenfels has been hard at
> work on an adaptive tuning program for several years now:
>
> http://www.adaptune.com/
>
> He defines "pain" as a sum of contributions from vertical dissonance,
> horizontal pitch shifts, overall pitch drift, and optionally other
> factors. Then his program minimizes the total pain.
>
> I'd be interested in comparing your approach with his . . . perhaps
> the main tuning list would be the right place for that . . .

Yes - Ive followed John's work - the methods are similar in many
ways, but also quite different in others. One of the major
differences seems to be that John's approach rests on the
use of familiar (just) intervals which form the basis of
the "pain" calculations (I think I sort of prefer John's
original "spring" terminology!) to define the tables used to adjust the pitches.

In the system used in the "string quartet" now at:

/makemicromusic/files/sethares/Recalled_Opus.mp3

the basic idea is to calculate the sensory dissonance at each
time instant and to move all sounding notes in the direction of
smaller dissonance. By using the parameterization of the
Plomp-Levelt calculations that Ive used before, its possible
to write this as a "gradient descent" algorithm. Hence one of
the strengths of this system is that it can be applied directly
to inharmonic sounds (even though it was not used so here -
since the partials of the violins are hamronically related.)
One of the strengths of John's approach is that it also takes
into account successive notes - all of my algorithms have
been "instantaneous".

You can clearly hear the action of the algorithm in the piece.
The compositional method used here was to start each tone on
its 12-tet location and to adapt the pitches (in real time
using a MAX patch). When the pitches begin close to JI intervals
such as a 12-tet fifth, then the adjustment is only a few cents.
But when the pitches begin at far from JI intervals (such as a
12-tet minor 2), then the sweeps of pitch are quite dramatic.
All of the pitch bending in the piece is done by the algorithm
in real time (though the whole thing was not performed in real
time - I cut and pasted sections together).

I've written about the method, and you can find a copy of
my 1994 JASA paper at:

http://eceserv0.ece.wisc.edu/~sethares/paperspdf/adaptun.pdf

>Beautiful work Bill!!

thanks

>Nice string timbres. Did you do that on the ASR? Sounds sweet.

Yes, these were violin (and viola) samples from K. Thomas'
collection of strings, which he made for the EPS/ASR.
He provides both sustained and pizzicato samples, so
I used both in various parts of the piece.
There are also some hints of sparkly things in the background -
made with a VL70.

>I like the implications of yer algo here in it's ability to deal with
>inharmonic timbres. How about a little tune to showcase that!???

I have a piece that was 95% finished about three years ago,
How long can it take to do the final mixdown?

Bill,

Really intriguing quartet (I did get *most* of it to download...). I
know you went into a more lengthy explanation on the 'how' of it, but
was this a piece written for exploration, or did you at some point
envision a live quartet making those kind of adjustments?

IOW, a strictly electronic/recorded incarnation, or something to be
performed at a time and date TBD?

> I have a piece that was 95% finished about three years ago,
> How long can it take to do the final mixdown?

How long do you have? :)

Cheers,
Jon