Billy Idol and Cat Power: Wolf Trap hosts an odd-couple concert pairing

History says odd billings, cool as they look on the theater marquee, just don't work in the concert realm. Some edgier pairings: The Monkees at their teenybopper peak brought along Jimi Hendrix as an opener; promoter Bill Graham tried introducing fans of then-faddish Led Zeppelin to beloved big-band jazzer Woody Herman at Fillmore East in 1969; and the Replacements were hired to support a 1989 tour for Tom Petty, a pairing that doesn't seem nearly as weird now as it was at the time. These allian...