Enigma

Given a melody, it builds several voices based on a harmoniztion of the melody. When music plays, the melody may be omitted – a true enigma.

The instruction:

perl  drenig.pl   file_lhom     rand_345     dur_100     with      orc

will produce a score named  enig345  and the corresponding midi file  enig345.mid.

All the parameters except the first are optional. Their interpretation is as follows:

file_scorename

Must appear; scorename is the name of the file to be processed by tondur.

rand_seed

The number seed is used to initialize the random numbers generator.

dur_value

the larger the value, the longer the piece. Duration is increased by repeating the "enigma" tune.

with

if specified, the enigma tune will be sounded with the other voices. If omitted, the enigma tune will not be heard.

orc

if specified, the voices will be assigned to various instruments; if omitted, they are all played on the piano.
The piano score may be unplayable by one pianist – then assume a player piano, or piano four hands, or two pianos.

The driver program executes two other programs:

1. tondur.pl

   The instruction is:

   perl  tondur.pl   file_scorename

   This reads a score and prepares the input for enig.pl , the file ouou.txt. It takes one obligatory parameter, the name of the input score.

   Examples:

   input:      lhom    (L'Homme Armé)

   
   {L'Homme Arme}
   key 1b
   names drm
   s5 /2 s/4 d/2 d/4 i l/2 s 3/4 r5 /4 r s5 p r6 r  r d/2 i/4 l/2
   s 3/4 r6 /4 r r s5 3/4 s6 /2 s/4 f/2 f/4 s/2 s/4 r 3/4 s6 /2 s/4 f/2 f/4 
   s/2 s/4 r/2 s/4 l/2 s/4 f m/2 r 3/4 p  s5 /2 s/4 d/2 d/4 
   i l/2 s 3/4 r5 /4 r s5 p r6 r  r d/2 i/4 l/2 s 3/4
   

   output:      lhomn0

   67 1/2
   67 1/4
   72 1/2
   72 1/4
   70 1/4
   69 1/2
   67 3/4
   62 1/4
   62 1/4
   67 1/4
   -1 1/4
   74 1/4
   .
   .
   74 1/4
   74 1/4
   72 1/2
   70 1/4
   69 1/2
   67 3/4
   

   The file inin.txt may contain key instructions (in this case key specifies 1 flat) and names instructions ( in this case, d r m ... = Do Re Mi ... = C D E ... ; rest is p). The program also recognizes comments: text in braces, both braces on the same line, text may not contain braces. Tones and duration may be specified as in my usual music editor, except that + and –  are not available for octave, and fractions cannot be written as numerator only.

2. enig.pl

   This program

   • receives its parameters from the driver
   • reads the file ouou.txt prepared by tondur.pl
   • analyzes the input, to determine the key of the piece – any of the keys that contain all the notes of the "enigma" melody. If no standard key fits, the program will use all the 12 (semi)tones.
   • writes the score.