The production of the transcriptions of BWV 439–507 has given us insight in the capabilities and limitations of The Pirate Fugues software.
The key observation is that our implementation of data-driven music composition simultaneously handles
The characteristic typically functions reasonably well on the scale of up to two measures as can be seen in the animations. The effect is convenient for users who have few experience with the rules of 1) voice leading, and 2) cadences, or find it difficult to consider the two aspects at the same time. Conventionally, the study of music theory is required to acquire the knowledge, and lot's of pratice to apply the rules with ease.
The Pirate Fugues software does not implement any criteria for musical consistency on the scale of an entire score. Therefore, it is perhaps not surprising that a subset of the suggestions as calculated by the software are entirely deranged from the score that surrounds it.
At present, the intuition and considerations of the user play an essential role in filtering the suggestions and making the final selection.
For experimentation, we have manually combined suggestions for 4 voices into a transcription with 5 voices for BWV 484, 494, 504, and 506. The soprano and bass voice are sufficiently apart to prevent voice crossing. The current search criteria of The Pirate Fugues software do not give suggestions for 5-voiced pieces in practice. Another factor is that the score database does not contain many scores with 5 or more voices.
Time-signature change exists in the scores BWV 444, 453, 490, and 504. In order to handle these four songs, we have split them into several pieces of invariant time-signature, and later put them back together. The splits are apparent from the video animations.
The data-driven music composition approach requires a large database of digitized scores. Every composition suggested by the software is consistent with bits and pieces of scores from the database. The Pirate Fugues implements the criteria in a deterministic fashion, that means the results are reproducible.
Our transcriptions of the scores BWV 439–507 should consist of 4 voices. Therefore, the scores in the database should predominantly contain four, or more voices.
Our database contains the following collections by J.S. Bach. On occasion, we have included works by Corelli, Telemann, Händel, or Mozart for experimentation.
BWV Description 225-231 Motetten 232-236 Messen 243-249 Magnificat, Passionen, Oratorien 250-438 Vierstimmige Choralsätze 525-530 Triosonaten 531-552 Praeludien und Fugen 553-560 Kleine Praeludien und Fugen, Johann Tobias/Ludwig Krebs 599-644 Orgelbüchlein 714-764 Choralbearbeitungen und Vorspiele 806-811 Englische Suiten 812-817 Französische Suiten 846-869 Das Wohltemperierte Klavier 1 870-893 Das Wohltemperierte Klavier 2 894-902a Praeludien und Fugen 971-987 Italian Concerto, Sechzehn Konzerte nach verschiedenen Meistern 989 Aria Variata 1014-1019 Sonaten fuer Violine und Cembalo 1066-1071 Orchestersuiten 1080 Die Kunst der Fuge 1090-1120 Orgelchoräle der Neumeister-Sammlung
The digital collections are provided to a large extent by MuseData of the Center for Computer Assisted Research in the Humanities at Stanford University.
We hope you enjoyed the string, piano, and organ arrangements.
The following 3rd party software and resources were used in the audio productions:
The pdf-documents and png-image previews of the final scores were generated using LilyPond. We are greatful for the assistance of the LilyPond community, most notably James Lowe, and Urs Liska (Schönberg-Lieder).
First measures of Mein Jesu, was für Seelenweh, BWV 487 as rendered by LilyPond:
Vocabulary: Getsemane, Belial
The transcriptions of BWV 440, 442, 444, 458, 469, 473, 477, 480, 485, 488, and 500 are engraved for piano.
For the scores in the booklet, we use the music font Gutenberg1939, that was kindly provided to us by its creator Abraham Lee.
The song titles are rendered in the Breitkopf-Fraktur which was conceived by the typographer Johann Gottlob Immanuel Breitkopf around 1750 in Leipzig. His father was the founder of the music publishing house Breitkopf & Härtel. The font has since been the favorite choice to decorate Baroque music.
The digital font is kindly provided to us by Dieter Steffmann.
The first author was partially supported by personal savings accumulated during his visit to the Nanyang Technological University as a visiting research scientist in 2012–2013. He'd like to thank everyone who worked to make this opportunity available to him.
Dem Meister Bach zu seinem Geburtstag,
jph & mm, Seoul/South Korea, March 2015
