Band’s worst artist? It is (4,7)
I believe the answer is:
dire straits
'band's' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'worst artist? it is' is the wordplay.
I cannot really see how this works, but
'worst' could be 'direst' (I've seen this in another clue) and 'direst' is located in the answer.
'artist?' could be 'ra' (Royal Academician, member of Royal Academy of Arts) and 'ra' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
'is' is found in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dire straits that I've seen before include "(in) great difficulty" , "Position of extreme distress" , "Great difficulties" , "Position of acute difficulty - pop group" .)