### Clue: Seth foolishly slept with women into big pop group (3,7)
### Answer: THE SHADOWS 
 ### Explanation: Definition: pop group
  **Anagram of**(foolishly) SETH + HAD(slept with, similar to the Biblical "knew") + [W(abbrev. for ­$$w$$omen, or woman?) **contained in**(into) OS(abbrev. for ­$$o$$ut$$s$$ize,big)
Defn: The late 50's instrumental pop group backing Sir Cliff when he and they first started out