Those cheap radio cassettes all had one thing in common: a shocking degree of wow and flutter. But they were all I could afford in the early 70s and they kicked me off into appreciating an amazing diversity of music. I remember going to my very first classical concert in the mid-70s in London (a young Riccardo Muti was conducting Beethoven's 7th, Strauss's Four Last Songs and the The Fairy's Kiss by Stravinsky). The clarity and immediacy of the sound and the absence of wow, flutter and hiss were revelatory!