María de los Ángeles Nieto Iglesias ( stage name, Ángeles Ottein; Algete, 24 June 1895 – Madrid, 12 March 1981) was a Spanish soprano, opera and zarzuela singer. She was the daughter of José Nieto Méndez, a notary of Burgos, and Erundina. Her siblings included Ofelia Nieto and José Nieto, who were also opera and zarzuela singers. [1] Ottein debuted in 1914 with a performance in ''Marina'', performing in opera and zarzuela for the next 40 years. [2]