What “Lempicka,” the mystifying new musical about Polish painter Tamara de Lempicka, needs more than anything else is turpentine.Two hours and 30 minutes, with one intermission. At the Longacre Theatre, 228 W. 48th Street.Gallons and gallons of it.Unfortunately, having garishly blared open Sunday night at the Longacre Theatre, it’s far too late for the creators to start over again on a blank canvas.And so, the ugly splatter that audiences are left to parse is a ridiculous two-and-half-hour Eurovision act with stratospheric delusions of grandeur.
