Case of unusual Dickensian family following pop singer (4,6)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Outer letters (case) of U [nusua] L + WELLER (surname of a father and son in Charles Dickens’s novel The Pickwick Papers ), after PA (Pop = colloquial terms for father). Singer with The Jam , then The Style Council , then later a solo musician.