[4][5] His performances, compositions, recordings and research are credited with expanding the guitar repertoire through advocacy for neglected composers and music, newly commissioned works and original arrangements.
[2][5][6][7][8] American Record Guide critic Kenneth Keaton wrote, "Leisner is among the finest guitarists performing … He has a probing intellect, finding insights in music that most others miss, and delivering them with a virtuoso technique.
[6] Over the next five years, wrote critic Allan Kozinn, Leisner "established a reputation not only as an exceptionally talented classical performer but also as a kind of musical investigator" unearthing obscure works for the guitar repertoire.
"[5] Continuing to rethink his technique, Leisner experimented with involving the larger muscle groups in the upper arm and shoulder and regained normal use of his fingers one by one, returning to 100% capability by 1996.
[29] Leisner has since helped cure a range of instrumentalists suffering from focal dystonia and other repetitive-stress injuries with the approach covered in his book on ergonomic technique, Playing With Ease.
[30][31][11][32] It discusses basic anatomy of movement, posture, alignment, the relief of tension, and practice and concert preparation tips, as well as his ideas about large-muscle engagement that cured him of focal dystonia.
"[5] Ian Gallagher of Guitar Review noted his propensity "to eschew the intellect for the soul" in compositions that made "a strong argument for the viability of contemporary tonal music and for the fusion of performer and composer in an age of specialization.
"[35] Critics have identified a "pedagogic but unpompous" approach to repertoire in Leisner's career,[36] distinguished by discoveries of overlooked composers, creative takes on classics,[37] and commissions and introductions of important new works.
[7][6][1][26] In addition to arrangements of Bach, Schubert and Glass, he has premiered works by Richard Rodney Bennett, Chester Biscardi, David Del Tredici, Osvaldo Golijov, Pierre Jalbert, Laura Kaminsky, Bun-Ching Lam, João Luiz, Ned Rorem, Peter Sculthorpe, Virgil Thomson and Randall Woolf.
"[28] Leisner has performed with cellist Zuill Bailey,[46] flutists Tara O'Connor and Eugenia Zukerman,[47] violinists Ida Kavafian and Mark Peskanov, vocalists Michael Kelly, Rufus Müller, Kurt Ollmann, Lucy Shelton and Sanford Sylvan,[39][48] and the St. Lawrence,[49] Ensō and Vermeer string quartets, among others.
[50] 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.
[10][58] 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.
[59] 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.
[61] In his arrangement of Schubert's song cycle, Die Schöne Müllerin (2022, with baritone Michael Kelly), Leisner eschewed the literal in favor of capturing the piece's essence.
"[62][63][64] 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.
[73][74][7] Richard Dyer characterized these pieces by their good literary judgment, imagination and taste in "taking poems from disparate sources and putting them into cycles that trace emotional progress and develop dramatic shape.
"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.