Elton hosts fair to cheer up (8)
I believe the answer is:
brighten
'cheer up' is the definition.
(I've seen this before)
'elton hosts fair' is the wordplay.
'elton' becomes 'ben' (I can't justify this - if you can you should give a lot more credence to this answer).
'hosts' indicates putting letters inside (inserted letters are welcomed or hosted).
'fair' becomes 'right'.
'ben' placed around 'right' is 'BRIGHTEN'.
'to' is the link.
Can you help me to learn more?
(Other definitions for brighten that I've seen before include "Illuminate, cheer up" , "Liven up" , "Berthing (anag.)" , "Polish" , "Provide illuminations" .)