ian,
you could try getting him to sing as if he has a cold or, as if he were 'duh' level stupid. the problem with most nasal sounds is not that they're nasal but, that's all there is to the sound. his larynx is probably a little on the high side so, singing in the two ways i suggest would be the easiest ways to get it lower. he probably won't do either enough because the correction will sound weird to him so, it would help to use a tape recorder and have him try varying degrees of correction so that he can hear how much correction he needs to fix the problem.
mike
| | |