Let it be said that Euterpe turned heads (4)
I believe the answer is:
stet
'let it be' is the definition.
(printing instruction to let a piece of text stand)
'said that euterpe turned heads' is the wordplay.
'heads' indicates taking the first letters.
The initial letters of 'said that euterpe turned' is 'STET'.
(Other definitions for stet that I've seen before include "indicates second thoughts are not always better" , "Print as is, don't alter spelling" , "'In printing, cancel a correction and leave it as it was (4)'" , "Notation meaning leave as is, don't alter spelling" , "Ignore instruction to change" .)