One of Liebermann's earliest successes was the Sonata for Flute and Piano Op.23, commissioned by the Spoleto USA Festival for flautist
Paula Robison and pianist
Jean Yves Thibaudet, a work which has gone on to become one of the most frequently performed sonatas in the flute repertoire. The was followed soon after by his
Gargoyles Op.29 for piano, a work which has become a staple of the solo piano repertoire. The
Steinway & Sons piano company commissioned Liebermann's 2nd Piano Concerto to celebrate the 500,00th Steinway piano built, and that work had its premiere at the Kennedy Center in 1992 with
Stephen Hough as pianist and
Mstislav Rostropovitch conducting the National Symphony. It was subsequently recorded along with Liebermann's 1st Piano Concerto for Hyperion with Hough and the composer conducting the BBC Scottish Symphony and was nominated for a Grammy in the Best Contemporary Classical Composition category. The success of Liebermann's Flute Sonata led flautist
Sir James Galway to commission Liebermann's Concerto for Flute and Orchestra Op.39, followed by commissions for the Concerto for Flute, Harp and Orchestra Op.48 That concert marked the first time a major orchestra broadcast a concert over the internet. In 2001 Liebermann was the Grand Prize winner of the Inaugural American Composers Invitational of the 11th Van Cliburn International Piano Competition, after the majority of semi-finalists chose to perform Liebermann's work Three Impromptus Op.68 for their final round recitals. Liebermann's second opera, Miss Lonelyhearts, to a libretto by
J.D. McClatchy based on Nathanael West's novel, was commissioned by
The Juilliard School as the final event in its centennial celebration. In 2012 Liebermann was invited to join the composition faculty of the Mannes College of Music at which time he became the founding conductor of MACE (Mannes American Composers Ensemble), a large ensemble devoted to the works of living American Composers. A year later, Liebermann was appointed head of the composition department, a position he held for five years. In 2014, Liebermann became the first recipient of the Virgil Thomson Award, a $40,000 prize given jointly by the American Academy of Arts and Letters and the Virgil Thomson Foundation, for the entirety of his vocal output. The
Royal Ballet, Covent Garden and
San Francisco Ballet jointly commissioned Liebermann's first full-length ballet, Frankenstein, premiered in London in 2016. In 2020, Liebermann was commissioned by Steinway & Sons for a second time, to compose a work for piano duet which was presented as a wedding present to the pianists Lang Lang and Gina Alice Redlinger after their wedding at the Palace of Versailles in Paris. Liebermann's catalogue of works runs to 150 opus numbers, including 4 Symphonies; 3 Piano Concertos and a Rhapsody On a Theme of Paganini for piano and orchestra; concertos for violin, cello, clarinet, organ, alto saxophone and trumpet; chamber works including 3 piano trios, a quartet and quintet for piano and strings; 5 cello sonatas and 6 string quartets; works for solo piano including 4 Piano Sonatas and twelve Nocturnes; and many works for voice with piano or chamber combinations. ==Musical characteristics==