Assembled, having to switch song (5)
I believe the answer is:
motet
'song' is the definition.
Both the answer and definition are singular nouns.
Maybe they are linked in a way I don't understand?
'assembled having to switch' is the wordplay.
'assembled' becomes 'met' ('meet' can be a synonym of 'assemble').
'having' means one lot of letters goes inside another.
'switch' says the letters should be written backwards (I've seen 'switching' mean this (switching direction)).
'to' written backwards gives 'ot'.
'met' placed around 'ot' is 'MOTET'.
Can you help me to learn more?
(Other definitions for motet that I've seen before include "Creating sacred piece" , "Certain one is morally superior" , "10 [COMPOSITION]" , "Anthem or church cantata" , "Short piece of church choral music" .)