Bandleader supple and cheerful (6)
I believe the answer is:
blithe
'cheerful' is the definition.
(similar in meaning)
'bandleader supple' is the wordplay.
'bandleader' becomes 'b' (this could be a standard abbreviation of which I'm unaware).
'supple' becomes 'lithe' (synonyms).
'b'+'lithe'='BLITHE'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for blithe that I've seen before include "Innocently happy" , "light" , "Joyful and unconcerned" , "Uncaring" , "Happy and maybe casual" .)