about Study 2

The Score
MIDI, “Authenticity”, MP3 and MP4 files


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: 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).
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).
Study 2 (MP4 videos, June 2017)
A complete performance using the Virtual MIDI Synth (with the Arachno SoundFont):
View online (with comments) / right-click to download mp4 (for better rendering).

A demonstration of the Assistant Performer's basic functions (track selection, speed etc.):
View online (with comments) / right-click to download mp4 (for better rendering).

A demonstration of the Assistant Performer's live conducting option:
View online (with comments) / right-click to download mp4 (for better rendering).
This is the latest version of the score (see the date stamp in the top left corner). Your browser does not support SVG


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.
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!