Thursday, 31 October 2019

Sound Synthesis Role Models 1 - Daphne Oram

All through my life, I have been inspired by many people who also had an interest in sound synthesis. Here is the first of an occasional series:

Daphne Oram (1925-2003)
Picture by Clusternote - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=61052771
One of the first British composers to create sounds electronically full-time, and a founder member of the BBC Radiophonic Workshop, where she worked from 1958-59. She did pioneering work on creating sounds by drawing with ink on 35 mm film stock, a technique known as 'Oramics'. With many people assuming that the earliest mechanical music reproduction was the music box or even the vinyl record, it is interesting to see that there are alternative techniques that have been used to produce music for a long time... 

Oramics and other opto-electronic devices like the Optigan use light to control the current that flows in an electrical circuit, and if the light varies, so does the current. If the light varies fast enough, then the current represents an sound - just like the varying current that an amplifier sends to a loudspeaker. 

When I was younger, I used to play around with opto-electronics a lot. The ORP12 was a common device (and you can still get them!) - it is a 'light dependent resistor (LDR), meaning that the resistance changes when light falls on it. The active substance is cadmium sulphide, and it comes in a small button package made of clear plastic - it looks exactly like one of those hobby or craft 'potting' projects where you put things inside clear resin.  The resistance of the ORP12 reduced as light fell onto the active 'window' at the end, and so you could use it to make all sorts of useful gadgets: from alarms that sounded when a light beam was broken, to things that could detect a square moving on a TV screen (Yes, the 'gun' accessories from video game consoles used to have an LDR at the end of a tube, and it detected the flashing light from the white square on the (probably a CRT) TV screen.) That was always one of the things about the ORP12 that surprised people - it responded quickly to light falling on it - you could modulate light at hundreds of Hertz (cycles per second). Other LDRs had even better frequency responses.




Picture by Kevan Davis - Flickr: Oramics Machine, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=17150394
In these digital times, it is interesting how electro-mechanical and opto-electronic devices have gradually vanished - and so the concept of putting something between a light and a photo-detector to vary the amount of light that falls onto the detector is probably unfamiliar to lots of people. 



By tpholland - Flickr: Oramics: waveform slides, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=24611604

But this is how the sound was stored on movie film - alongside the picture, a wavy line looking very much like a modified audio waveform was used to generate the sound that you heard in the cinema. The idea of drawing in ink on film to make sounds flows from seeing film with an 'optical soundtrack' and understanding how it works. 


By Oramics Machine details 2.jpg: linearclassifierderived work: clusternote - This file was derived from: Oramics Machine - details 2.jpg:, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=32980388
By Iainf 09:33, 12 July 2006 (UTC) - Own work, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=941554
Nowadays, movie sound is stored in a virtual 'container' that holds digital bits of data that represent the pictures and the sounds, and there's nothing much to look at, and certainly no easy way to draw the data bits... 

(All images via commons.wikimedia.org - Captions contain attribution information.)

Daphne Oram is the first of my role models because she made music from pictures!

Daphne Oram - Wikipediahttps://en.wikipedia.org › wiki › Daphne_Oram
Daphne Oram Collection | Goldsmiths, University of Londonhttps://www.gold.ac.uk › ems › oram Daphne Oram | British Music Collectionhttps://britishmusiccollection.org.uk › composer › daphne-oram
Daphne Oram on BBC4 - BOILER ROOMhttps://boilerroom.tv › recording › daphne-oram-bbc4
Culture - The woman who could 'draw' music - BBCwww.bbc.com › story › 20170522-daphne-oram-pioneered-electronic-music


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