All the books and documentation I have ever read on giftedness indicate that regardless of the prior educational environment etc, when placed in the right environment a gifted child will fly until they reach the level they would have been at without the restrictions previously imposed.
Could you cite two or three of the most convincing of these books etc.? I strongly doubt this assertion, but I'm not sure I've ever seen well conducted research that addresses it, and I'd be very interested to do so.
ETA: actually I'll start a new thread for this general issue, which is wider than music.
Specifically re Hersch, I suspect that there might be some myth-making going on here; some of it just doesn't hang together. His younger brother was learning the French horn, yet he heard classical music for the first time ever at 18? Why hadn't he heard classical music from the horn as his brother practised? It's not a quiet instrument... The article gives the impression that at 18 he had never heard any classical music, couldn't read or write music, had never had an instrumental lesson, yet at 19 he was at a conservatory studying composition, playing his own music on the piano from written scores he'd produced himself... This is less like a late genius story, and more like a "child brought up alone in forest found to speak Greek" story. Did he in fact go to school, study music there, learn to read music, play the recorder or something, just not get inspired until later? That would be more credible.
