Prakseda Marcelina Kochańska, known professionally as Marcella Sembrich, was a Polish coloratura soprano. She is known for her extensive range of two and a half octaves, precise intonation, charm, portamento, vocal fluidity, and impressive coloratura. Her voice was regarded as flute-like, sweet, pure, light, and brilliant. She had an important international singing career, chiefly at the New York Metropolitan Opera and the Royal Opera House, in London.