Composing with probability

It was rather a play than a game.


Around 1975, there was introduced on TV program "the composition by computer". Therewas discribed some programs (Basic, Fortran and Cobol) as well as programming principles.
However, ther was neither any computer around me nor even a pocket calculator in my house. I wanted to do it. So I managed to understand this principles and arange in my own to actually compose something.

[collecting data]

First, we must collect several pieces which had been already published and had a similar atmospheres or image. In my case, I collected Beatles initial numbers, my most favorite ones. Next if a score had flats or shaps, I changed it so that it must have only mormal C, D, E and so on.
I prepared the table below.

I made changes of musical scale into a data using the score.

For example, if F follows D and G follows F, then I got a table below.

For example, if there was "CDE, CDE, GDECDED", then I changed "C->D, D->E, E->C, C->D, D->E, E->G, G->D, D->E, E->C, C->D, D->E, E->D" to get table bilow.

[Calculateing probability]

I first calculated probability taking note of figures of each line. Using them, I calculated a range to which random numbers would be limited when I would to generate them as from 0 to 1. For example, I got table below by calculating using then line of D.

If random numbers were from programs, you don't have to do any more. In my case, I got them by throwing dice, so had to correct them if necessary.


I determined the first sound and a length of note. With the data described above, I got random numbers by throwing dice and compose stepwise by inputting musical scales.

[Evaluating my composition]

My composition had its certain atmosphere as a whole, but was not a good one because having its poor climax or development. If enjoying your own composition by yourself, you could not violate copyright. However, I don't know what difficulties may happen if you sell your composition.

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