... or perhaps Strauss (one of them).
I don't
think Strauss was Austrian...?
And certainly didn't "die young."
</nitpick>
Also, @Mira is 100% correct to note that there were innumerable "Austrian Composers" and it doesn't have to be one of the "Big Names."
Nevertheless, I think we should presume that it was indeed one of those Names (likely Mozart):
(a) Jim clearly has someone
particular in mind, and it's doubtful he'd delve into classical-music-minutiae to unearth J. Random Niemand. &:
(b) Mozart isn't
just "an" Austrian composer, he's widely held to be the greatest composer ever, with a deeper understanding of music, and grasp of "perfect" musical forms, than any other. I myself am far too plebian to judge (or even understand) such claims; but that seems to be a common report by "people who know."