A very enjoyable film, providing you know how to watch old musicals / mysteries. It may not come close to Agatha Christie or even Thin Man mysteries as a film noir, but it's much more interesting than your typical "boy meets girl" or "let's put on a show" backstage musical. As a musical, it's no Busby Berkley or Freed unit, but it can boost the classic "Coctails for two" and the weird "Sweet Marijuana". The film runs in real time during a stage show, opening night of the "Vanities", where a murder - and soon another - is discovered backstage. Is the murderer found out before the curtain falls? Sure, but the search is fun, even though somewhat predictable and marred by outbursts of comic relief (luckily in the shape of the shapely goddess of the chorus girls, Toby Wing). The stupid cop is just a bit too stupid, the leading hero is just a bit too likable, the leading lady a bit too gracious, the bitchy prima donna bit too bitchy, and the enamoured waif a bit too self-sacrificing, but as stereotypes go, they are pretty stylish. There's a bevy of really gorgeous chorus girls, who are chosen even better than the girls for a Busby Berkley musical of the same period, who sometimes tend to be a bit on the plump side. Yes, this film could have been much better than it is, and the Duke Ellington number is an embarrassment, but if you enjoy diving into old movies, this will prove to be a tremendously tantalizing trip.