Feature of Berg’s music composed almost in A (9)

I believe the answer is:

atonalism

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'feature of berg's music' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps there's a link between them I don't understand?

'composed almost in a' is the wordplay.
'composed' indicates anagramming the letters.
'almost'+'in'+'a'='almostina'
'almostina' anagrammed gives 'ATONALISM'.

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I've seen this clue in The Times.

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