Like some of the others here, it was Rush's 1981 album 'Moving Pictures'. It was the first album I EVER bought in the summer of 1983. However, I don't consider it to be a "prog" record in the "purist" sense. Likewise, I've NEVER considered Rush to exclusively be a "prog" band either. They certainly have elements of it, however, what sets them apart from the pack is that they never left behind the ROCK when all was said and done. The same can't honestly be said about some of the prog bands who came before.
If I have to label them, I'd prefer calling Rush progressive hard rock. Am I splitting hairs? Perhaps. Be that as it may, they unquestionably paved the way for Queensryche, Savatage, Fates Warning, Dream Theater, and Crimson Glory ( the latter band being CRIMINALLY overlooked within the genre, in my opinion ) to name just a few. Great comments everybody (
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