Lights a fire under section of concert orchestra (7)
I believe the answer is:
torches
'lights' is the definition.
(torch is a kind of light)
'of concert orchestra' is the wordplay.
'of' indicates a hidden word.
'TORCHES' is hidden within 'concert orchestra'.
'a fire under section' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for torches that I've seen before include "Fires" , "Hand-held lights" , "Sets on fire" , "Flashlights" , "Sets alight" .)