An Early Compiler for
Computer-produced Music

Computer History Vignettes

By Bob Bemer

By autumn of 1956 I had gotten my PRINT I system for the IBM 705 installed satisfactorily at a number of sites. There were many other things I wanted to do, and IBM had their own list of what they wanted me to do. But there was latitude.

Christmas was coming up, and IBM had this shiny 705 in the ground-floor showcase at 590 Madison Avenue. Surely a little Christmas music was in order.

Note that this was not my original idea; music had been played on computers before. Even at IBM, on the 701, three years before my venture, Joe Teagarden had employed roughly the same technique to get different tones. Read his story -- he thinks he may have been first.

But I was a software man -- a compiler man. I should be able to marry the two. So I wrote a modest translator from a solfeggio notation, input on punch cards. The variables were 1) the key, 2) the tempo, in quarter notes per minute, 3) the number of such quarter notes to the bar (i.e., the time), 4) the note itself, 5) sharping or flatting, 6) the duration of the note in 16th notes (optionally 32nd), and 7) octave change up or down.

The notation was like "mi-4,mi-4,mi-4,mif-4 mi-4,sol-4,fa-4,la-4, re-4,do-4,ti-2,do-2,re-4,sol-4,mi-12 ..." Which gave one "Oh Little Town of Bethlehem ..." (the octave-changing technique is not shown here -- I've forgotten it).

The tone was played, as usual, by tapping off some operation code or other hardware-unique point, which got triggered at the end of a program loop of varying length. It got "ooh - aah" responses like a fireworks show.

To show the real virtuosity of the notation, I made a deck of cards for "Entry of the Gladiators", that old circus tune. I figured that was often played on a calliope (another mechanical music device), which didn't have the best timbre either. So it would be a good match.

I couldn't resist varying the tempo. Finally set it to 1000 quarter notes a minute, a rate at which a calliope would have broken down, probably. Wow!

I sent a tape recording of that to Dr. Henry Tropp at the Smithsonian Institution, when he was just getting going in the computer history field. He eventually returned it, and it's somewhere among my office detritus. I don't know if I can find an old-fashioned tape player to run it.

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