He was also flautist of the orchestras of Minneapolis, Los Angeles and Rochester. In 1914, during his collaboration with the Minneapolis Symphony Orchestra, he met Maude Peterson, a pianist who frequently accompanied him and became his wife. In 1917, the Los Angeles Flute Club played a musical in his honor and De Lorenzo was appointed the first Honorary Member of the association.
From 1923 to 1935 he was professor for flute at the Eastman School of Music, where one of his students was Julius Baker, considered one of the greatest American flutist of his generation. After his retirement, De Lorenzo focused on composition and writing of theoretical publications. Works such as Saltarello and Pizzica-pizzica are a homage to the characteristic sounds of the traditional music of his native town. In 1951 he released the book My complete story of the flute, a result of intensive research by De Lorenzo which made him one of the most eminent flute pedagogues of the 20th century.
All of his research material was donated to the University of Southern California, on October 25, 1953. In the same year, he received an honorary doctorate of the Washington International Academy of Rome and was godfather for the newly formed flute club in Milan. On August 29, 1955 the Los Angeles Flute Club organized a concert playing his compositions for his 80th birthday. De Lorenzo died in his home in Santa Barbara, California. The International Flute Competition "Leonardo De Lorenzo", held every two years in Viggiano from 1997 to 2013, was dedicated to him.
Compositions
Appassionato, for flute, op. 5
Giovialità, for flute and piano, op. 15
Serenata, for flute and piano, op. 16
2 Pieces for flute and piano, op.17
2 Pieces for flute and piano, op.18
2 Pieces for flute and piano, op.19
2 Pieces for flute and piano, op.20
2 Pieces for flute and piano, op.21
2 Pieces for flute and piano, op.22
2 Pieces for flute and piano, op.23
Saltarello, for flute, op. 27
Carnevale di Venezia, for flute
Nove grandi studi
I tre virtuosi, for three flutes, op. 31
I seguaci di Pan, for four flutes, op. 32
Non plus ultra, for flute, op. 34
Pizzica-Pizzica, for flute, op. 37
Suite mitologica, for flute, op. 38
Idillio, for flute and piano, op. 67
Improvviso, for flute and piano, op. 72
Sinfonietta (Divertimento Flautistico), for five flutes, op. 75
Trio Eccentrico, for flute, clarinet and bassoon, op. 76
Trio Romantico, for flute, oboe and clarinet, op. 78
I quattro virtuosi (Divertimento fantastico), for flute, oboe, clarinet and bassoon, op. 80
Capriccio, for four flutes, op. 82
Didactic works
L'Indispensabile. A complete modern school for the flute (1912)
