In the 1960s and 70s, to encourage experimental approaches and connections to the new music of the time, Universal Edition published a series of pieces intended for classroom use. These were designed to be accessible to both children with, or without, previous music experience. Composer, Sound artist and Musician Duncan chapman has curated a selection of some of these pieces from the British Music Collection, splitting them into six categories: Codes, Performing, Games, Journeys, Mobiles and Media.
Dashing Away by Alan Brett is an example of a type of "code score". The effect of the piece is created by the addition of simple elements.
Alan Brett was also active in The Scratch Orchestra (along with several other composers who have pieces in this series). These are two of the text scores he made during this period:
The notation of Dashing Away has a strong resemblance to Stockhausen's "Plus/Minus" notation. This is part of Stockhausen's Spiral from 1968:
Pre-Mediaeval Metrics : Gavin Bryars. Another piece in the BMIC collection that uses a very similar method of composition. Two sounds, one long one short.
You can find the full exhibiton on the Google Cultural Institute here: http://bit.ly/2oPmzJ4