Talk about new slogan repeated (5)
I believe the answer is:
chant
'slogan repeated' is the definition.
I can't judge whether this defines the answer.
'talk about new' is the wordplay.
'talk' becomes 'chat' (I've seen this in another clue).
'about' means one lot of letters goes inside another.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'chat' enclosing 'n' is 'CHANT'.
Can you help me to learn more?
(Other definitions for chant that I've seen before include "Mantra" , "A monotonous song or rhythmic call" , "Type of group singing" , "Intone (psalm)" , "Vocal music" .)