### Clue: Distorted notes in passport, say, held by a decrepit thing (4,4)
### Answer: ACID ROCK 
 ### Explanation: Definition: Distorted notes
 ID(short for "identity papers", an example of which/say, is a passport) **contained in**(held by) [A + CROCK(a decrepit/worn out or ruined thing, a vehicle, say) ].
Defn: A type of rock music partly defined by distorted notes from electric guitars.