Forgetfulness leads to our best violin being smashedsmashed (8)
I believe the answer is:
oblivion
'forgetfulness' is the definition.
(I know that oblivion is a type of forgetfulness)
'our best violin being smashedsmashed' is the wordplay.
I cannot really understand how this works, but
an anagram of 'violin' is 'livion' which is present in the answer.
The remaining letters 'ob' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'leads to' acts as a link.
Can you help me to learn more?
(Other definitions for oblivion that I've seen before include "State of being mentally withdrawn or blank" , "State of being altogether forgotten" , "lack of fame" , "State of unawareness" , "State of being totally unconscious" .)