### Clue: No rocker provided key's final change (6)
### Answer: MODIFY 
 ### Explanation: Definition: change
 MOD(a member of the subculture in late 50s/60s whose members clashed with rival subculture, the Rockers) + IF(provided, as in "I'll be there if you are there") + **last letter of**(…'s final) "key".