Re: [MMM] Improvisation on pitches from a recording of a song

Hi Carl,

> This sort of thing could be useful not only for bird song, but for
> extracting scales from traditional music!

Yes. It can do it already if the music is on a wind
instrument of suitable timbre such as a flute,
or something which is very amenable to the technique.

> May I ask, how do you cope with note transitions? How do you decide
> what discrete pitches to choose? Surely the thrush does not sing in
> discrete pitches.

Yes you are right, that's maybe not so very reaalistic of it
to make it into a scale, though it is interesting as a kind
of found scale coming out of the interaction between the
program and the bird song.

It takes the average pitch during a glissandi and when it
slides far enough makes a new pitch. You can play it with
pitch glides between them all I suppose strictly speaking
it should try and transcribe it using continuously varying
pitches.

I just tried slowing down the thrushes song and it does have
many large pitch glissandi. Some other birds are a bit more discrete
in the pitches they sing.

> My suggestion for extracting scales from melodic performances is as
> follows. Normal audio signals plot energy over time. After continuous
> pitch extraction, we have pitch over time. If we apply a time-domain
> transform to *that*, we have 'pitch frequencies' -- the amount of time
> the performer spent playing each pitch in the entire performance (the
> duration of musical tones is typically great compared to the period of
> musical pitches, so I think we're OK here). We can now slice the pitch
> continuum into octaves, and in each octave hopefully see a manageable
> number of Gaussian lumps (if not, we might say there is no discrete
> scale abstraction used in the performance). When we superimpose these
> octave slices, a majority of lumps hopefully coincide. Finally, the
> local maxima of this summed function are written to a Scala file.

Does this make sense? Perhaps we should take this to the tuning
list...

Yes could do that. FTS extracts the notes as a sequence
of volume, time and frequency triples. So one could analyse
those however one wants to try and extract the scale.

At present it just analyses them by using a tolerance
factor. It orders all the pitches in ascending order,
using an interval of equivalence set by the user,
or it can just use the highest pitch found as the interval
of equivalence if that is appropriate.

Then it walks up the scale and bundles the pitches
using the tolerance limit as it finds them.
So you set the tolerance limit high enough to allow
for variability in pitch but low enough to distinguish
pitches that should be distinguished so will depend on
the context. Or one could just use all the pitches
found in ascending order by making the tolerance
level 0.

I don't do anything about weighting by the duration of the pitches, but one
could do that too, especially since longer duration pitches
are perhaps likely to be pitched more exactly, or heard
with more exactness of pitch too, I mean a grace note
of just a hundredth of a second for instance may not
be so exactly pitched as a one second note for instance.
So maybe one could take that into account. I could
add an option to FTS to print out all the pitches found
as pitch / volume / duration triples for anyone to analyse
as they please using their own software too.
Well it is visible in the interface but
as three rows of numbers - you could just
use those too copy / paste and use them
as input to ones program.

I've cc'd this reply to the main tuning list.

I'll take a look at the next few digests
in case there are any replies on this
particular thread. It's relevant to what I'm working
on in the programming right now so for me it's
"work" :-). But with the high volume of posts
there I'll probably miss some replies if it
gets followed up much - that doesn't mean I'm
uninterested, just working hard that's
all right now on the FTS 3.0 release.

Thanks,

Robert

----- Original Message ----- From: <MakeMicroMusic@yahoogroups.com>
To: <MakeMicroMusic@yahoogroups.com>
Sent: Wednesday, April 13, 2005 10:20 PM
Subject: [MMM] Digest Number 1187

>
>
> There are 3 messages in this issue.
>
> Topics in this digest:
>
> 1. Re: Rhapsody for Dan Stearns (mp3)
> From: Margo Schulter <mschulter@...>
> 2. Improvisation on pitches from a recording of a song thrush
> From: "Robert Walker" <robertwalker@...>
> 3. Re: Improvisation on pitches from a recording of a song thrush
> From: Carl Lumma <ekin@...>
>
>
> ________________________________________________________________________
> ________________________________________________________________________
>
> Message: 1
> Date: Wed, 13 Apr 2005 00:37:55 -0700 (PDT)
> From: Margo Schulter <mschulter@...>
> Subject: Re: Rhapsody for Dan Stearns (mp3)
>
>
>
> On Tue, 12 Apr 2005 Aaron Krister Johnson wrote:
>
>> I'm behind on my posting, but I did listen--I enjoyed this....is this in >> your
>> 2/7 comma 'temperament extraordinaire'?
>>
>> All best,
>> Aaron.
>>
>> > <http://www.bestii.com/~mschulter/RhapsodyForDanStearns1.mp3>
>
> Hello there, Aaron and all.
>
> Actually I'm just catching up myself, since I've just downloaded some
> of your pieces on your newly formatted page
>
> <http://www.akjmusic.com/works.html>
>
> For now I'll just say that your a cappella renditon of _Most Blessed
> of Mornings_ in a Neidhardt temperament is beautiful; the _I Dream of
> Tibet_ piece in 7-tET is most wonderful; and _Melancholic_ is for me a
> fascinating mixture or medley of styles, and from a theoretical
> viewpoint one might ask how much of this is specific is to the 53-EDO
> tuning, and how much to some other creative elements -- but a
> consummate piece of music.
>
> There's also some Prent Rodgers and Dan Stearns I'm been catching up
> on, another reason for me to post again soon.
>
> It's curious that you mention this tuning (the temperament extraordinaire
> based on Zarlino's 2/7-comma meantone), since it's what I've mostly
> been playing in lately, and indeed I'm trying to get some pieces ready
> for recording.
>
> This piece, however, is in something I did in part as a change of pace
> -- 11-tET (or 11-EDO, as people prefer), based on a main scale of a
> kind which I came upon in the Spring of 2002 and which it turned out Dan
> Stearns had earlier found. This basic type of pattern is:
>
> 0 2 4 6 8 9 11
> 0 218 436 655 873 982 1200
>
> Part of the fun was finding synthesizer timbres so that the 6-step
> interval (about 654.55 cents) would serve musically as a "fifth." The
> fact that it's considerably narrow of 3:2 makes possible a special
> effect: when the excellent 11-tET major third (just wide of a pure
> 9:7) expands to a fifth, both voices move by a semitone of 1 step
> (about 109.09 cents), a progression I use to open the piece. This
> progression calls for some steps outside the above basic hexatonic
> scale, here:
>
> 5 6
> 1 0
>
> However, the final cadence formula is available within the basic
> scale:
>
> 9 11
> 8 6
> 2 0
>
> This might be approximately described as a xentonal variation on a
> 13th-century European formula where an outer minor sixth (here very
> close to a just 14:9) expands to an octave and an upper minor second
> to a fourth. Both the original and this 11-EDO variation are very
> moving and and powerful and beautiful, each in its own way.
>
> Anyway, sooner or later I wanted to document this tuning/timbre, but
> the desire for a "change of pace" gave me an immediate incentive.
>
> Again, thank you both for your response to this piece, and for your
> beautiful music.
>
> Peace and love,
>
> Margo
>
>
> ________________________________________________________________________
> ________________________________________________________________________
>
> Message: 2
> Date: Wed, 13 Apr 2005 20:08:21 +0100
> From: "Robert Walker" <robertwalker@...>
> Subject: Improvisation on pitches from a recording of a song thrush
>
> Hi there,
>
> http://www.robertinventor.com/improvisation_on_thrush_song_pitches.mp3
>
> [4 Mb]
>
> Robert
>
>
> ________________________________________________________________________
> ________________________________________________________________________
>
> Message: 3
> Date: Wed, 13 Apr 2005 13:34:20 -0700
> From: Carl Lumma <ekin@...>
> Subject: Re: Improvisation on pitches from a recording of a song thrush
>
>>Hi there,
>>
>>http://www.robertinventor.com/improvisation_on_thrush_song_pitches.mp3
>>
>>[4 Mb]
>>
>>Robert
>
> Fascinating! How'd you do it? -Carl
>
>
>
> ________________________________________________________________________
> ________________________________________________________________________
>
>
>
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[Replied on tuning.]

-C.