The most common and most likely answer to this crossword clue is the 9 letter word GREGORIAN
I've seen this crossword clue in The Times
G
R
E
G
O
R
I
A
N
More clues leading to the result GREGORIAN
- Visiting old lady, I initially revel in such chant
- Pope’s choice of Scotsmen?
- Calendar girl upset Federer and Scotsman
- One of two men maybe chants?
- A pope’s man metamorphosed in a novel
- Papal gag or rein, after a fashion
- Sort of calendar relative keeps — for example, gold one
- Particular calendar one received, kept by Harry in retirement
Buddy explains!
The straight part
We know that "such chant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case such chant = gregorian.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.