Study 2 began in the spring of 2010 as part of the process of developing and
debugging Moritz’ Assistant Composer and Assistant Performer modules.
It began as a test case for the use of MIDI control texts written into standard notation scores
by the Assistant Composer (using capella’s CapXML format),
but ended as my final farewell to standard, 19th century music notation.
Standard notation
The MIDI and score of Study 2a, completed in July 2010.
The MIDI and score of Study 2b1, completed in October 2010. Non-standard notations
The MIDI and scores of Studies 2b2 and 2b3, completed early in May
2011.
The MIDI and scores of Study 2c, completed in March 2012.
Study 2, (the final version) has Study 2c3.1
as its immediate predecessor.
These scores all sound very similar. They use the same input
krystals and therefore have the same form, but the palette structures changed slightly for Study 2b1, again
for 2b2 / 2b3, and again for Study 2c, so the audible results are slightly
different. There are however considerable differences both in the way these scores look
graphically and in the way they are saved as computer files.
Study 2 is also about polyphony.
Study 1 had been homophonic, and I wanted to be able to work on polyphonic music.
Avoidable complications arose however, because Study 2 was originally restricted
to standard music notation:
in standard music notation, bars ‘add up’ according to fixed meanings
of the symbols. Those fixed meanings are related to a common, humanly perceptible
tempo.
there is no humanly perceptible reference tempo in this piece. The durations of
event symbols (chords) are defined in milliseconds. Bars ‘add up’
at the millisecond level. The main standard music notation symbols are used because
they are the most powerful and legible set of symbols that we have, but tuplets
are not necessary for defining durations here. This is a major difference between
writing scores on paper, and writing them as computer files (in which temporal
information can be stored separately from the graphics).
Tuplet
brackets could, however, be added as annotations, if that would help the score to
be more legible. Musical performance practice is actually learned by listening...
Notation is always an aide memoire...
Moritz can now write scores in which standard chord symbols can be placed freely
at any point on any staff, making the composition (and automatic transcription)
of polyphonic music much simpler. The durations, and the symbols which represent
them, are now decoupled from most assumptions about perceived time. There is still a correspondence between a particular spatial direction and the
direction of the time arrow, but that is all. (Left-right corresponds to before-after
in Study 2.)
Following the lessons of Study 2, I think is now possible to define standard ways of writing
SVG+MIDI files for any of the world’s music notations, not just those that
read left to right and use Western music symbols.
I am currently
(June 2017) working on simplifying and generalizing the format that Moritz generates.
A
further hope is that
the ability to store and communicate performance practice in
computer files will lead to
composers developing written music that breathes
again... music that can be phrased meaningfully in humanly perceived time...
The Score
Study 2’s graphics and MIDI information are now stable, but the internal details of the SVG format
still have to be finalized (June 2017).
Recordings:
Study 2c3.1 (MP3, March 2012)
This is an old mp3 recording, using the Microsoft GS Wavetable Synth.
Study 2c3.1 was the immediate precursor of Study 2 (the final version).
This is the latest version of the score (see the date stamp
in the top left corner).
Background
Earlier versions
Study 2a is the original 2010 score. Study 2b2 uses elementary symbols
(like
the coloured numbers in the Assistant Composer’s “Why ornaments?” documentation) spread across simple,
polyphonic systems. But in Study 2b3 the standard duration class
symbols are associated with ranges of duration — as in my earlier, handwritten pieces
and my transcription of Curtis Roads’
Sonal Atoms. Study 2b3
replaces the simple symbols of 2b2 by standard chord symbols on standard, five-lined staves. The symbols are spaced
across the systems in the same way as they would be in standard notation. Study
2b3 looks more like
Study 2b1, except that
the duration classes now have millisecond durations that are stored directly inside
the score.
In Study 2c, I developed the re-ordering and distribution of voices
on staves (with maximum two voices per staff). Study 2 (the final
version) was immediately preceded by Study 2c3.1.
The structure of Study 2
Each bar in each staff contains between 1 and 7 chords, corresponding to the values
in a krystal strand. In the original standard notation (Studies 2a and 2b1), I had
to make the bars ‘add up’ in the parallel staves, so the bars originally
had lengths of 1, 2 or 4 (simple) quavers, and the chords used invisible tuplets per bar
as necessary. Each chord in the top staff was some kind of (tuplet) quaver in
the manner of Study 1.
In the final version of Study 2, each duration class represents a band of durations (for
example, a quaver has a duration greater than 400ms and less than or equal 800ms).
There are 12
independently defined event types for the top staff, each of which has a defined
inner structure, (millisecond) duration and hence a defined duration class. These event types are instantiated irregularly over
the course of the piece according to the values in a krystal. Bars happen at the
krystal’s strand level. Thus each bar
has a particular (millisecond) duration that is the sum of the durations of the component chords in the top staff.
The other two staves are also constructed from krystals (using contouring to shape the directions in which the voices move), whereby
the durations are fit as equally as possible into the known bar durations. This also determines the duration classes of the chords
in staves 2 and 3.
Summary: the durations of the event symbols (chords) in Study 2 are neither related to each other by a common, humanly perceptible tempo,
nor do the duration class symbols have precise meanings that relate to such a tempo.
Technical realization
When a performance of a score is started, the Assistant Performer first creates
a ‘MIDI-Score’ containing lists of MIDI messages waiting to be sent.
This information can either be played using default timings by the assistant alone,
or by a live performer who triggers the events in real time.
In 2a and 2b1, the MIDI information is inferred from the graphics — noteheads
in the chord symbols, and visible control texts attached to the chords in the (CapXML)
score.
In 2b2 and 2b3, the MIDI information is read entirely from
custom extensions to the standard
SVG format in which they are written. This decouples the (spatial) graphics
from the temporal and MIDI information. The Assistant Performer can easily create
a ‘MIDI-Score’ from the temporal and MIDI information alone, without looking at the
graphics. Arbitrary graphics can thus be associated with the temporal and
MIDI information.
In a little more detail: At the top level in this extended SVG file format, MIDI
instructions, together with the default timings necessary for their machine performance,
are associated with symbols at the System, Staff, Voice and
Chord levels. System, Staff, Voice and Chord are abstractions which
relate to the finite size of pieces of paper and the need for parallel event symbols
(polyphony). Note that these abstractions do not imply any particular notation.
They are just a standard hierarchy of containers which allow parallel time axes
(Staves, Voices) to be represented on 2-dimensional screens or pieces
of paper. The shapes and complexity of the graphics depend entirely on the authoring
software. The symbols can be of any shape and complexity. Staves could be notated
vertically as far as I'm concerned...
The Assistant Composer now writes the specialized graphics, the default temporal
information and the MIDI information into the score's file(s), using information
taken from its input palettes. The graphics are just for human consumption, for
reading ahead, performing, structural analysis etc.
Perspectives Universality: Any kind of notation can be
embedded in this extended SVG format. I have in mind: Gregorian Chant, standard
notation, ordinary language text, non-standard notations of any kind — even those
which are read vertically, or are animated etc. The format can also, with a little
work, probably be used to connect timings to areas inside scanned images. Navigation: Even if the MIDI information
is omitted, the default object/event timings can still be associated with positions
within 2-dimensional graphics of any kind. Imagine a cursor following an audio or
video recording of an ancient or 20th-century manuscript score, or being able to
click on the graphics/image to jump to a position in a recording. Maybe one is learning
Chinese... Annotations: It should be possible to add
annotations to such extended SVG files without losing the non-graphic extensions
and making them unperformable. The annotations,
which would be purely for human consumption, could have academic uses or be performance
instructions. For example, my Assistant Performer knows nothing about slurs
because they mean something too complex to be translated into MIDI instructions.
The performance of a slur (phrasing) is not something that can be mechanically fixed.
Phrasing is intimately related to the uniqueness of a particular performance, and
has to be understood as part of a living performance practice tradition. Modern
SVG editors, such as Corel Draw, now have tools that can easily be used to draw
slurs... Interactivity: SVG is a format which can
be displayed by most of today’s browsers, and it has interactive capabilities
which I hope to exploit further in future. On the agenda are user performance of
on-line scores, and the assisted performance of unfettered scores in real performances...
MIDI, “Authenticity”, MP3 and MP4 files
Moritz produces MIDI output, but the sound of a MIDI file is more or less undefined
unless one has access to a system like the one on which it was created. This is
especially the case in extreme examples like Study 2, which contain rapid sequences
of control messages.
My original reference synthesizer for Study 2 was the Microsoft GS Wavetable Synth
(supplied as part of the Windows operating systems), which I
played using either Moritz’ Assistant Performer or Windows Media Player.
In June 2015, I unfortunately hit a bug in the Microsoft GS Wavetable Synth, that
crashed Chrome, so Chrome decided that it was a security
problem, and banned it from use in Web MIDI. I now use the Arachno soundFont, either
with the Virtual MIDI Synth
or my own Resident SF2 Synth.
The present recordings were made by balancing all the settings as well as I could
using one or other of these synthesizers.
Other MIDI performance systems may give a completely different impression of the
piece.
March 2012: Quicktime, for example, not only has different timbres and balance from
my reference systems (when playing MIDI files), but it also appears to respond more
slowly to control messages.
This can mean that a patch change, for example, may only take effect after
the chord for which it was intended. In Study 2, that is pretty catastrophic. Not
only the balance, but even the logic is wrong! Quicktime has been
known to give up
altogether on my computer, two or three bars before the end of the piece. It still
sometimes omits the final chord in the performance.
It is to avoid such problems, that I have converted all the original MIDI files
to mp3s for this website, and have made some new mp4 videos of the Assistant Performer
performing.
The mp3 files were created by simply converting
the Assistant Performer’s MIDI output with WAV MP3 Converter. This converter not only converts between
many different
audio formats, it can also convert MIDI files to audio. I also tried converting
the MIDI files to wav, but the increase in quality is too small to justify the increased
file sizes (and corresponding load times) on this website.
Remember that it is the information in the score and corresponding MIDI files that
counts here: The audio files are presented only to ensure that the sounds heard
at this website are logically correct. Stronger, more transparent, better
balanced performances can doubtless be produced from the MIDI files by specialists
using more powerful synthesizers and/or post-production software.
This is a matter of expertise and interpretation. In other words:
I would very much like to hear other interpretations of the score and MIDI originals,
maybe using other sounds, synthesizers and/or post-production software!