Various Small Fires and Code

Friday, September 4, 2015


I'm working towards translating to ABC and LilyPond output via generic traversals over the Beam Syntax. This opens the door to special notations in LilyPond output like drum notes.

Thursday, September 3, 2015


I've added a very rough implementation of Humdrum-like output printing. The output is for debugging purposes (there is a problem with pitch conversion to or from LilyPond) and so doesn't attempt to properly match Humdrum: the output has to be readable (obviously) and decipherable i.e. it has to preserve information so it works for showing bugs.

Strictly following Humdrum would impede the second goal.

Wednesday, September 2, 2015


I've added interval addition and subtraction as per the algorithm in Francois Pachet's "An Object-Oriented Rerpresentation of Pitch-Classes, Intervals, Scales and Chords: The basic MusES" (page 9).

Both are a bit untested, I really should write Quick Check properties and tests at some point.

Tuesday, September 1, 2015


I've worked on Pitch and Intervals as a prelude to sorting out the LilyPond relative pitch transformation.

A proper set of functions to manipulate pitches and intervals should provide the tools to encode the relative pitch transformation fairly simply. My previous ad hoc attempts were just confusing.

Monday, August 31, 2015


I've commit the initial work on supporting quasiquoted LilyPond fragments as input syntax.

Outputting LilyPond is still to do.

Sunday, August 30, 2015


I've pushed a new set of modules that implement a simpler, monophonic notelist - just notes and rests (and tuplets), no chords or grace notes.

This notelist should be able to support transformations like transposition.

Saturday, August 29, 2015


I've added linebreaking to ABC output so that it only prints four bars per line.

It's an intention I have for Payasan that the score output should be good enough for "feedback" whilst using the system, but real scores are expected to be hand edited after generation. Fixing line length to four bars rather than making it configurable seems in tune with this.

My previous designs for score languages have always suffered from having too many configuration options.

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About Me

Disambiguating biog as there are a few Stephen Tetley's in the world. I'm neither a cage fighter or yachtsman. I studied Fine Art in the nineties (foundation Bradford 1992, degree Cheltenham 1992 - 95) then Computing part-time at Leeds Met graduating in 2003. I'm the Stephen Tetley on Haskell Cafe and Stackoverflow.