Agnesi, the famous bass, whose real name was Agniez, was born July 17, 1833, at Erpent, Namur. He studied at the Brussels Conservatoire, under Boselet and Fetis, and in 1853-55 gained the concours de Rome. He brought out an opera, 'Harold le Normand' (1858) with indifferent success, and subsequently abandoned composition for singing. For the latter purpose in 1861 he received instruction from Deprez, and became a member of Merelli's Italian Opera Company, under the name Luigi Agnesi, during a tour through Germany, Holland, and Belgium.

On Feb 10, 1864, he first appeared at the Italiens, Paris, as Assur in 'Semiramide,' with the sisters Marchisio, and was engaged there for several seasons. In 1865 he was engaged at Her Jamesty's Theatre, where he first appeared with Mruska, May 22, as the Prefect in 'Linda de Chamouni,' and during the season he played Assur and Figaro (Le Nozze), and also sang at the Philharmonic, on each occasion with fair success.

In 1871, on his return to England, where he remained until his death, Feb 2, 1875, he enjoyed a greater reputation, not only in opera at Drury Lane (1871-74), but as an oratorio and concert singer at the Handel and provincial Festivals, at the Sacred Harmonic, at the Philharmonic, etc. In addition to the parts above named, he played with success Pizarro ('Fidelio'), Mikheli in the solitary Italian performance of 'Les deux Journess,' June 20, 1872, the Duke in 'Lucrezia,' etc., and showed himself in all an accomplished actor and musician, devoted to his art.

Special mention may be made of his Assur, which he sang in true Italian style, with Titiens and Trebelli as Semiramide and Arsace, a cast of which opera has never since been equalled; also of his delivery of the bass part of Crotch's 'Palestine,' in a style of music wholly unfamiliar to him.