Woodwind section standing by the river (5)
I believe the answer is:
reeds
'by the river' is the definition.
I can't judge whether this defines the answer.
'woodwind section standing' is the wordplay.
'woodwind' becomes 'reed' (reed is a kind of woodwind).
'standing' suggests taking the first letters.
The initial letter of 'section' is 's'.
'reed'+'s'='REEDS'
Can you help me to learn more?
(Other definitions for reeds that I've seen before include "They vibrate to produce the sound of various musical instruments" , "pens for sheep" , "Tall stiff marsh grasses" , "Stops" , "Thin pieces of cane in musical instruments" .)