Base is possible to overlook without artist's contribution (7)
I believe the answer is:
ignoble
'base' is the definition.
(similar in meaning)
'possible to overlook without artist's contribution' is the wordplay.
I cannot really understand how this works, but
'without' could be 'no' and 'no' is found within the answer.
This may be the basis of clue (or it may be nonsense).
'is' is the link.
Can you help me to learn more?
(Other definitions for ignoble that I've seen before include "'Base, dishonourable (7)'" , "Inferior" , "Lacking dignity" , "Cheap" , "Not honourable, low" .)