[12] Also in 1898, he took on the role of musical director for a West End show, conducting the theatre orchestra for the run of "The Topsy-Turvy Hotel" by Victor Roger and Lionel Monckton.
[3] In 1901, Leoni wrote the music for an operatic version of Hans Andersen's children's story, Ib and Little Christina, to a libretto by Basil Hood.
[14] The Manchester Guardian later said that "the music, though clever and attractive in many ways, was too realistic and too Southern to reflect the Northern symbolism of Andersen's story, and that its peculiar vein of passion was out of place.
"[20] Later in 1904, Leoni published a song-cycle entitled "Fairy Dreams", which was premiered by four well-known soloists, Suzanne Adams, Muriel Foster, Ben Davies and Kennerley Rumford (the husband of Clara Butt).
[22] A later critic said of the work, "Hokum, but any opera that begins with three crashes, a very loud cock-crow, a chorus shouting in fake-Chinese and then launches into a vehement unaccompanied solo … has clearly got something going for it.
[23] The one-act piece, which depicts melodramatic events in and around a San Francisco opium den, had a libretto by Camillo Zanoni, based on the play The Cat and the Cherub by Chester Bailey Fernald.
[24] The London performances, conducted by André Messager with Antonio Scotti as the villain, Cim-Fen, were well received: The Observer wrote of the score, "It is never for an instant dull.
Henry Wood conducted the premiere of The Bells, Leoni's "vocal scena" for baritone and orchestra, set to Edgar Allan Poe's poem of the same name.
[27] In 1911, Leoni's cantata, Golgotha, depicting the Gospel story of Christ's passion and crucifixion, was premiered in London, with soloists including Gervase Elwes and Clara Butt.
[28] The last large-scale work that Leoni composed before leaving his English domicile was Francesca da Rimini, a one-act piece based on a play by Francis Marion Crawford, given in a French version by Marcel Schwob at the Opéra Comique, Paris, in 1914.
[3] His later operas were Le baruffe chiozzotte, to a libretto based on a play by Carlo Goldoni (1920), La terra del sogno and Falene, to libretti by C. Linati (1920).
[3] Thereafter it was rarely performed, but it came to public attention again when the conductor Richard Bonynge made a complete recording of the piece in 1975 starring his wife, Joan Sutherland, and the veteran Tito Gobbi as the villain.