<cite>Music</cite> in the key of blah, by Peter Marks
An actress radiating youthful vigor and sensuality is not a great fit for Desiree Armfeldt, the soignée Sondheim heroine whose most ravishing days are behind her. So it's an unfortunate truth that Catherine Zeta-Jones is not ideally cast as regretful, wistful Desiree in Trevor Nunn's virtually never-right revival of the suavely farcical <cite>A Little Night Music</cite>. Still, you have to award Zeta-Jones showing-u…