The most common and most likely answer to this crossword clue is the 9 letter word CLASSICAL
I've seen this crossword clue in The Times
C
L
A
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S
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C
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L
More clues leading to the result CLASSICAL
- Sort of music / from Ancient Rome?
- Girl wreathed in lilac cultivated from an earlier time
- Like some music I composed, mostly with style
- Traditional girl is enthralled by military leader almost completely
- Attic maybe calls for conversion, like this one inside
- Traditional college girl I rang, disconnected halfway through
- Refined female visiting Channel Islands and California
- Faithfully recorded Callas performing outside broadcast on Radio Three
- Cold girl I term almost ‘highbrow‘?
- Traditional taste of Monbazillac is Salciccia knocked back
Buddy explains!

The straight part
We know that "Sort of music/from Ancient Rome?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sort of music/from ancient rome? = classical.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CLASSICAL mean?
CLASSICAL noun- One that is classical in some way; for example, a classical economist.
- Of or relating to the first class or rank, especially in literature or art.
- Of or pertaining to established principles in a discipline.
- Describing European music and musicians of the late 18th and early 19th centuries.
- Describing art music (rather than pop, jazz, blues, etc), especially when played using instruments of the orchestra.
- Of or pertaining to the ancient Greeks and Romans, especially to Greek or Roman authors of the highest rank, or of the period when their best literature was produced; of or pertaining to places inhabited by the ancient Greeks and Romans, or rendered famous by their deeds.
- Conforming to the best authority in literature and art; chaste; pure; refined
- Pertaining to models of physical laws that do not take quantum or relativistic effects into account; Newtonian or Maxwellian.