WH Auden - Base Words Are Uttered

Base words are uttered only by the base
And can for such at once be understood,
But noble platitudes:--ah, there's a case
Where the most careful scrutiny is needed
To tell a voice that's genuinely good
From one that's base but merely has succeeded.

WH Auden

http://www.poemhunter.com/poem/base-words-are-uttered-2/