Surely you know that telltale moment, at the start of many great Golden Age musicals, when the curtain rustles, the lights glow warmer and the violins start churning out the schmaltz. Whatever sadness the story has in store, the sound from the pit tells you all will be well.

There’s a wonderful moment like that in “Soft Power,” which opened at the Public Theater on Tuesday in a coproduction with the Center Theater Group of Los Angeles. A golden curtain sweeps away to reveal, silhouetted on a scaffold in a cloud of vermilion light, a 22-piece orchestra , digging into the opening notes of Jeanine Tesori’s triple-crème score. If an audience ever sighed as one, it does here.

What’s strange is that this musical moment does not arrive until 20 minutes into the show, by which point we have already seen — twice — a main character being stabbed in the neck and left to die on a Brooklyn street. The character will survive; we know that because he is based on the playwright , David Henry Hwang, who survived just such an attack in 2015. Even so, the promise of those violins turns out to come with lots of provisos.

Such is the cleverness, and confusion, of “Soft Power,” which the authors call a “play with a musical.” Bristling with ideas that rarely get dramatized, let alone in such imaginative form, it is something of a miracle but also something of a muddle, the ideas scrambling over one another for prominence and the ingenious form unable to corral them. Still, those ideas — about the betrayals inherent in love, democracy and musicals themselves — are too exciting and important to dismiss by quibbling them to death.