Land of Hope … It’s inspired by Elgar’s last muse (9)
I believe the answer is:
ruritania
'land of hope' is the definition.
(fictional land created by Anthony Hope)
'it's inspired by elgar's last muse' is the wordplay.
'inspired by' is an insertion indicator (some letters breathed in or 'inspired' by others).
'last' suggests the final letters.
'muse' becomes 'urania' (Urania is an example).
The last letter of 'elgar' is 'r'.
'r'+'urania'='rurania'
'it' going within 'rurania' is 'RURITANIA'.
(Other definitions for ruritania that I've seen before include "Fictional land of romance" , "mythical land" , "Land of Hope ..." , "world of romance?" , "RA Air Unit (anag.)" .)