Cracking solo — Coltrane finally free (5)
I believe the answer is:
loose
'free' is the definition.
(I know that free can be written as loose)
'cracking solo coltrane finally' is the wordplay.
'cracking' indicates anagramming the letters.
'finally' indicates one should take the final letters.
The final letter of 'coltrane' is 'e'.
'solo' anagrammed gives 'loos'.
'loos'+'e'='LOOSE'
(Other definitions for loose that I've seen before include "Free or immoral" , "Unconfined" , "Unrestrained" , "Not restrained or attached" , "Unleash" .)