Prakseda Marcelina Kochańska, known professionally as Marcella Sembrich, was a Polish dramatic 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.

The Barber of Seville, or The Useless Precaution is an opera buffa in two acts composed by Gioachino Rossini with an Italian libretto by Cesare Sterbini. The libretto was based on Pierre Beaumarchais's French comedy The Barber of Seville (1775). The première of Rossini's opera took place on 20 February 1816 at the Teatro Argentina, Rome, with designs by Angelo Toselli.