A couple of notes of little distinction (2-2)

I believe the answer is:

so-so

'of little distinction' is the definition.
(so-so means average)

'a couple of notes' is the wordplay.
'a couple of notes' can mean two replacements for 'note'.
'note' becomes 'so' (musical note).
'note' becomes 'so' (musical note).
'so'+'so'='SO-SO'

(Other definitions for so-so that I've seen before include "Tolerable, indifferent" , "OK, but nothing special" , "Native of Seville" , "Neither good nor bad" , "Informally, only moderately good or well" .)

I've seen this clue in The Times.

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