Encourage pop singer to record, last of all (4)
I believe the answer is:
prod
'encourage' is the definition.
(thesaurus)
'pop singer to record last of all' is the wordplay.
'last of all' indicates one should take the final letters.
The final letters of 'pop singer to record' are 'PROD'.
(Other definitions for prod that I've seen before include "Poke, stimulate into action" , "Incite to action (with a stick?)" , "Poke with a stick" , "Push with pointed instrument" , "Give a reminder" .)