They learn choral arrangement in two seconds (8)
I believe the answer is:
scholars
'they learn' is the definition.
The definition suggests an adverb but the answer is not.
'choral arrangement in two seconds' is the wordplay.
'two seconds' can mean two replacements for 'second'.
'arrangement' indicates anagramming the letters.
'in' means one lot of letters goes inside another.
'second' becomes 's' (common abbreviation).
'second' becomes 's' (common abbreviation).
'choral' is an anagram of 'cholar'.
's'+'s'='ss'
'cholar' going into 'ss' is 'SCHOLARS'.
Can you help me to learn more?
(Other definitions for scholars that I've seen before include "Cross Hal mixed with pupils" , "Students or learned people" , "Learned people, usually academics" , "Pupils, students" , "Very learned persons" .)