Clue: Four notes describing a meeting (4-1-4)
Answer: TETE-A-TETE
Explanation: Definition: meeting
TE may be a variant of TI or SI, a 'note' of the sol-fa, or a flattened TI; either way, there are four of them around ('describing') 'a'. Like 3D, diacritics may be desirable – circumflexes on the first and third E, and a grave accent on the A – but as the letters go into the lights as capitals, even the French may then omit them, despite the disapproval of the Académie française.