It's basically common sense. Everyone knows that things like "obscurity" are relative, and that depending on what a person knows, that person is going to make assumptions about the kinds of things other people know and about which things are or aren't obscure.
So my question is: Which of the following composers would you personally consider obscure? Just go down the list and check a "y" if you consider the name obscure and an "n" if you don't. No other explanation, just a yes or a no answer.
>Leonin
>Perotin
>Petrus de Cruce
>Busnoys
>Ockeghem
>Obrecht
>Isaac
>Clemens non Papa
>Lassus
>Gesualdo
>Veracini
Handel
>Haydn
>J.C. Bach
>M. Haydn
>Vanhal
>Mozart
>Beethoven
>Rossini
>Schubert
>Schumann
>Brahms
>Dvorak
>Bruckner
>Rimsky-Korsakov
>Satie
>Nielsen
>Schmidt
>Zemlinsky
>Stravinsky
>Bartok
>Hindemith
>Carter
>Petrassi
>Young
>Davies
I'm curious about how much variation there'll be in people's answers.