Ignoring lines, Ryan Gosling organised a group chant (9)
I believe the answer is:
singalong
'a group chant' is the definition.
'singalong' can be an answer for 'chant' (I've seen this before). I'm not certain of the 'a group' bit.
'ignoring lines ryan gosling organised' is the wordplay.
'ignoring' suggests deleting specific letters.
'lines' becomes 'ry' (abbreviation for railway).
'organised' indicates an anagram.
'ryan'+'gosling'='ryangosling'
'ryangosling' with 'ry' removed is 'angosling'.
'angosling' with letters rearranged gives 'SINGALONG'.
Can you help me to learn more?
(Other definitions for singalong that I've seen before include "people making music together" , "in which everyone joins in?" , "Informal group musical activity" , "social occasion" , "chant" .)