100 Schilling Johann Strauss

Austria's silver commemorative program of the 1970s used a debased .640 fine alloy rather than the traditional .900 standard, a deliberate cost-control decision by the Austrian Mint as silver prices climbed through the decade. The Strauss issue sits in the middle of that program, neither the first nor the last to use this specification.

Johann Strauss II died in 1899, making 1975 the 76th anniversary of his death — an odd choice for commemoration, until you note that Vienna was deep into a decade-long cycle of cultural jubilees that often bent anniversaries to fit minting schedules rather than the reverse.