A longtime performer with the New York City Opera from the 1960s through the 1980s, he notably created the role of Professor Risselberg in the world premiere of Gian Carlo Menotti's The Most Important Man in 1971.

[2] He is best known for his portrayals of Adolfo Pirelli in the original Broadway production of Stephen Sondheim's Sweeney Todd: The Demon Barber of Fleet Street (1979) and Teddy in the off-Broadway 1987 revival of Cole Porter's Gay Divorce at the Martin R. Kaufman Theatre.

[7] In 1972 he recorded the role of Parpignol in Giacomo Puccini's La bohème with the NYCO in a cast that included José Carreras as Rodolfo, Elisabeth Carron as Mimi, and Nancy Shade as Musetta.

[8] Other roles Romaguera sang with the NYCO included Monostatos in Mozart's The Magic Flute (1969);[9] Goro in Puccini's Madama Butterfly (1969);[10] the Village Drunk in Dmitri Shostakovich's Lady Macbeth of the Mtsensk District (1970);[11] the Chief Justice in Giuseppe Verdi's Un ballo in maschera (1971, 1974);[12] Nathaniel in Jacques Offenbach's The Tales of Hoffmann (1972);[13] Little Bat in Carlisle Floyd's Susannah (1972);[14] Normanno in Donizetti's Lucia di Lammermoor (1974); Spoleta in Puccini's Tosca (1974);[8] Slave in Richard Strauss's Salome (1975);[15] Dr.

In 1967 he portrayed Nicolas Orsini in the world premiere of Alberto Ginastera's Bomarzo with the Opera Society of Washington; a role he recorded on disc and repeated a year later at the NYCO.

[23] In 1982 he portrayed Captain Pirzel in the United States premiere of Bernd Alois Zimmermann's Die Soldaten with conductor Sarah Caldwell and the Opera Company of Boston.