‘In the West we have come to venerate the young and dismiss the old, valuing the rough, unvarnished, ‘authentic’ voice of youth, as if it is all of importance because it is therapeutic or esteem-raising for the young creator.’ 
Howard Goodall is writing in the context of commenting on the place of improvisation in music education.
Goodall’s target is the idea that musical improvisation can take place outside of a particular musical tradition, style or practice. What some describe as improvisation is no more than exploration, doodling (and that has its place).
Viewed as an aspect of a particular musical practice improvisation is to be seen as the fruit of long induction into stylistic norms and heritage. Examples such as Indian Classical and Jazz practices allow for improvisation through hard gained knowledge of templates and structuring devices that are painstakingly learnt. Thus, for Goodall, improvisation is a musical practice unfit for examination at GCSE in view of the relative immaturity of those at this stage.
In the new National Curriculum for Music in England Key Stage 1 children will be ‘experimenting with sounds’, at Key Stage 2 they will be ‘improvising and composing music’. However, knowing what we do about children’s musical development at these stages, it will be extremely unlikely that improvisation will be informed by the idioms and stylistic features of particular musical practices. More likely, improvisation will have a specific pedagogic purpose as supported by Dalcroze and Orff, for example. Improvisation will mean playing with musical material helping its easy assimilation as well as working as an exploratory phase of composing music.
At Key Stage 3 the National Curriculum states that young people should be taught to ‘improvise and compose’. Might this suggest a commitment to improvisation within a particular musical practice while maintaining it as an exploratory phase of composing?
This would require thinking of Key Stage 3 as an induction into a particular musical practice(s). This doesn’t much resemble current orthodoxy. Anna Gower refers to our ‘bitty approach’. 
However, if we concentrated on a particular musical practice at Key Stage 3 as modeled by say, Rock School, Samba School, 18th Century Neapolitan Orphanage Conservatoires or Jazz Academies, or whatever, improvisation could flourish as a distinctive practice.  As it is that bitty approach with its thousand flowers blooming misses the mark.
Time for a summer break.
 Speech given at the Sunday Times Festival of Ideas 2014. See http://www.howardgoodall.co.uk/news/what-future-for-music-in-schools
 See http://mrsgowersclasses.wordpress.com/2014/06/28/day-one-entry-26-jun-2014/
 I am reminded of Tom Gamble’s Key Stage 3 curriculum devised in the early 1980s in his Hertfordshire school dedicated entirely to 20th century avant-garde music.