From Goddess, at the Public. Photo: Joan Marcus If you need someone to sing like a deity, you could do a lot worse than Amber Iman, whose voice can traverse several states of matter in quick succession. It can be deep and solid as obsidian, then fluid as water, fluttering into a riff like air, or zapping into a held note with the charge of plasma—all with remarkable ease and control. Iman’s been an if-you-know-you-know musical-theater star for the last few years, excellent in Shuffle Along and