Leisner is as recognized for his artistic breadth as for the virtuosity of his playing. As a composer, his wide-ranging influences include Britten,
Stravinsky,
Bartok,
Heitor Villa-Lobos and
Philip Glass, among others, and more broadly, pop, folk and jazz music. Critics have identified a "pedagogic but unpompous" approach to repertoire in Leisner's career, distinguished by discoveries of overlooked composers, creative takes on classics, and commissions and introductions of important new works.
Performing Critics characterize Leisner's playing for its blending of control and dexterity with deep expressivity, color, intimacy and spontaneity. Composer and musicologist Angelo Gilardino stated, "what sets Leisner apart is the refinement of his phrasing, which he imbues with clear, convincing and original intentions. He does so in an elegant manner … His playing is authoritative, without trying to appear so." Reviews of Leisner's solo recitals have highlighted, among others, his performances of
Ginastera's "
Guitar Sonata," Villa-Lobos's "Twelve Etudes," Bach's Chaconne and Lute suites, and his own "Nel Mezzo: Sonata." flutists Tara O'Connor and
Eugenia Zukerman, violinists
Ida Kavafian and
Mark Peskanov, vocalists Michael Kelly, Rufus Müller,
Kurt Ollmann, Lucy Shelton and
Sanford Sylvan, and the
St. Lawrence,
Ensō and
Vermeer string quartets, among others. Along with Leisner's publishing efforts, it helped to establish the composer's significance, distinctive romantic personality and melodic gifts through works
American Record Guide described as "fascinatingly and superbly crafted" and performed with "conviction, sensitivity and complete technical assurance." Reviews described it as "some of the most stimulating Bach of recent years" With
Heitor Villa-Lobos: The Complete Solo Guitar Works (2000), Leisner made one of the first recordings of the composer's recently discovered original 1928 manuscript for his "Twelve Etudes." Breaking with convention, he brought out the work's lush melodies, rhythmic interplay and nuance rather than approach it as a showcase for dexterity and speed. Reviews contended that the recording offered startling new insights, making "a persuasive case for the composer's first thoughts [and] a valuable addition to the guitar catalog." Like his work on Mertz, the latter recording advocated for Matiegka, another overlooked guitar composer, as highly inventive and central to the guitar repertoire of his era through assertive, elegant interpretations. With
Music of the Human Spirit (2002), Leisner turned to contemporary work—by Ginastera, Glass, Rorem, Sculthorpe, Harrison, Poulenc and Richard Winslow—chosen for its rebalancing of heart, mind and spirit over the purely cerebral.
Favorites (2012) was a kind of summation of the guitar repertoire, mixing daunting "pinnacle" works (Britten's "Nocturnal," Bach's Chaconne and
Paganini's "Grand Sonata") with lighter, under-recognized character pieces by
Alexander Ivanov-Kramskoi.
American Record Guide predicted that Del Tredici's piece, symphonic in scope, with a sonata-like opener, lively fugue, an "achingly beautiful" slow movement, and flamenco finale, would become a become a seminal guitar work.
Composing Critics distinguish Leisner's compositions for their emotional and dramatic power, openness to diverse musical forms, idioms, instruments and inspirations, and "performability," a quality sometimes lacking in non-players' works. Inspired by a
Nathan Englander story in which a group of World War II-era Jews evade the concentration camps by chance when they board a train of circus performers, it begins at a moment of immediacy where the story ends, when the escapees must perform to maintain their cover. Critics likened its stark contrasts, obsessive character and emotional journey through conflict, poignancy and defiance to works by
Hector Berlioz. Leisner has also written several works for orchestra. "Embrace of Peace" (1991, commissioned by the Fairfield Orchestra), inspired by a painting by George Tooker, was described as a "striving, passionate and hopeful" tone poem whose imaginative combinations of instruments and dissonances set up warm and satisfying resolutions. "Wayfaring" (2022, guitar and full orchestra) is a three-movement work written for guitarist
Pepe Romero, based on the folk song/spiritual, "Wayfaring Stranger." ==Writing, teaching and other professional activities==