Irina Rivkin walks onto the stage — small and so unassuming that she almost seems shy, but for her easy smile and banter. She grabs two microphones and stands in front of a peculiar electronic gizmo with pedals and sings a pretty tune in a pretty voice. So far so good. She taps a pedal to finish the live loop recording and adds a catchy, vocal percussion riff. Then she sings along with both, adding harmonies. On top of that, she layers more clear, pitch-perfect vocals. Rivkin’s lyrics are poetic, powerful. Her music is multi-layered, complex, both ethereal and earthy; …