There you go, 45 rpm discs - when I first bought them (Can't Buy Me Love by the Beatles, so 1964?) they were 6/8d, exactly three for £1. Which was a bu$$er if you'd only got a ten-bob note as a birthday present. LPs were 37/6d. Record players had speeds of 16, 33, 45 and 78.
And then the cassette. When they first came out it was like something out of the space age. I never quite got 8-track cartridges, although they were of better recording quality than cassettes. The cartridges were just too big though.