¿Qué es punk?

¿Qué es punk? ¿Qué es más importante, la letra o la música?
¿Acaso no es punk la letra de Another brick in the wall de Pink Floyd?

O por ejemplo ésta:

"The Logical Song" (Supertramp) written and composed by Roger Hodgson

When I was young, it seemed that life was so wonderful,
a miracle, oh it was beautiful, magical.
And all the birds in the trees, well they'd be singing so happily,
joyfully, playfully watching me.
But then they send me away to teach me how to be sensible,
logical, responsible, practical.
And they showed me a world where I could be so dependable,
clinical, intellectual, cynical.

There are times when all the world's asleep,
the questions run too deep
for such a simple man.
Won't you please, please tell me what we've learned
I know it sounds absurd
but please tell me who I am.

Now watch what you say or they'll be calling you a radical,
liberal, fanatical, criminal.
Won't you sign up your name, we'd like to feel you're
acceptable, respecable, presentable, a vegtable!

At night, when all the world's asleep,
the questions run so deep
for such a simple man.
Won't you please, please tell me what we've learned
I know it sounds absurd
but please tell me who I am.