Having received the shocking news that Elsmorian has never heard Tommy, I went back and listened to it again myself. While I was listening I read the Wikipedia article, which says "Townshend's later interest in synthesizers is foreshadowed by the use of taped sounds played in reverse to give a whistling, chirping sound on 'Amazing Journey'". I thought "really? never noticed" and listened to it once more.
It's funny when you revisit things you've listened to casually before and discover new depths. I only even noticed these funny chirpy sounds when I listened to them again just now, while they add a wonderful other-worldliness to the song, reinforcing the idea that it's all a vision inside Tommy's head. They sound great even today, but it was only when I realised how fantastic they must have sounded in 1969, when the album was released, that I could appreciate it properly. Bear in mind that I've been brought up in a musical culture where synthesisers are mundane (we call digital ones keyboards now) and sounds like that are trivial to create with the audio equivalent of the universal constructor, the waveform editor. I think it's rather sad that my appreciation of it is jaded by having heard similar sounds hundreds of times before, as just another instrument.
It all reminded me of Terry Pratchett's remarks about conjuring in his interview with Stephen Briggs in The Discworld Companion (my copy is the second edition), where he explains that he would probably enjoy a Discworld play, with its improvised, amateur special effects, more than a Discworld film, with big-budget CG:
I suppose I'm saying it's the difference between magical tricks being done by a genuine wizard and by a stage conjuror. The wizard does marvellous things but it's, well, magic and therefore in a sense mundane. Yawn yawn, he's produced another damn pigeon, well, that's magic for you. But when you know it's being done by a conjuror with a hearing aid and a day job down at the building society, and all achieved by springs and elastic and secret pockets, this makes it much more interesting. Any fool can be a wizard, but you have to be clever to be a conjuror.
I think you can say the same for any look back at past innovations. It's difficult to appreciate the cleverness of past inventors when the modern man looks at their inventions and shrugs — to him, they're just a prosaic part of his world, no more amazing than a flint knife would have been to a caveman.