The New York Times gave extraordinary reviews of Gary Lehman's March 2008 Metropolitan Opera debut as Tristan in Tristan und Isolde, stating, "Something of a savior has risen from the rubble... Mr. Lehman is handsome and athletic... Wagnerians long hardened to diminished expectations for this strenuous role had every reason to be happy on Tuesday night... Surviving Tristan is in itself an accomplishment. Mr. Lehman did more than survive, and the Met must be pleased to have him." Mr. Lehman made both his house and role debuts that night opposite the Isolde of Deborah Voigt. As a result of his successful debut, the Metropolitan Opera immediately engaged him to sing the role of Alwa in Berg's Lulu in 2010.

Mr. Lehman's exciting future engagements include Tristan in Tristan und Isolde for the Stars of the White Nights Festival in St. Petersburg, Russia (Maestro Gergiev conducting); Erik in Der Fliegende Holländer with the Savonlinna Festival in Finland; Stathis Borans in The Fly with Los Angeles Opera, the U.S. premiere of the LA-commissioned opera written by Oscar-winning composer Howard Shore (Lord of the Rings) and conducted by Plácido Domingo; Don José in Carmen for Hawaii Opera Theatre; Tannhäuser with Norwegian National Opera; and Alwa in Lulu for the Metropolitan Opera. He will also be returning to the Metropolitan Opera next season to cover both Tristan and Siegmund.

In addition to Mr. Lehman's Metropolitan Opera debut, his 2007/08 season has included performances as Florestan in Fidelio with Opera Roanoke, his return to Los Angeles Opera as cover artist for both Tristan and Florestan, and the tenor soloist in Beethoven's 9th Symphony with the Columbus Symphony. In Mr. Lehman's three short years singing the Heldentenor repertoire he has amassed a stunning amount of critical acclaim in Wagner's most challenging roles, including Tannhäuser with Theater Erfurt in Germany; his Heldentenor debut as the title role in Parsifal with Los Angeles Opera; his first Siegmund in Die Walküre in Long Beach Opera's production of Graham Vick and Jonathan Dove's version of Wagner's Ring Cycle; and also as Samson opposite Denyce Graves in Samson et Dalila with Orlando Opera.

Mr. Lehman has, for the last decade, appeared as a leading baritone with opera companies throughout North America, including the New York City Opera (Marcello in La Bohème, Oreste in Gluck's Iphigénie en Tauride), Arizona Opera (title role in Eugene Onegin), Atlanta Opera (Zurga in Les Pecheurs de Perles), Pittsburgh Opera (Ford in Falstaff and Roucher in Andrea Chénier), Michigan Opera Theater (Ford), Opera Company of Philadelphia (Taddeo in L'Italiana in Algeri), Boston Lyric Opera (Count Almaviva in Le Nozze di Figaro, Eisenstein in Die Fledermaus and Taddeo), Opera Theatre of St. Louis (Count Almaviva and Germont in La Traviata), Portland Opera (John Sorel in The Consul and Count Almaviva), Montreal Opera (Marcello and Silvio in I Pagliacci), Opera Omaha (Silvio and baritone soloist in Carmina Burana), Lyric Opera of Kansas City (Germont, Sharpless in Madama Butterfly and Belcore in L'Elisir d'amore), Kentucky Opera (Ford,Germont,and Guglielmo in Così fan tutte), and Utah Opera (Ford, Marcello and Guglielmo), Toledo Opera (Eisenstein), Mississippi Opera (Valentin in Faust), Chautauqua Opera (Ford), Shreveport Opera (Belcore), Opera Idaho and Opera North (Escamillo in Carmen), and Wildwood Park for the Performing Arts (Guglielmo in Così fan tutte).

He has appeared on the concert stage in Carnegie Hall debut with the Orpheus Chamber Orchestra (Bruschino Padre in Rossini's Il Signor Bruschino), Saint Louis Symphony as Dr. Falke in Die Fledermaus, Omaha Symphony (Father in Hänsel und Gretel), and Dallas Symphony Orchestra.

As a member of the Lyric Opera Center for American Artists, he appeared in more than 90 performances on the main stage, in addition to singing the roles of Figaro in Il Barbiere di Siviglia and Falke in Die Fledermaus. Gary Lehman was the recipient of a 1993 Robert Jacobsen Study Grant from the Richard Tucker Foundation, and appeared in the PBS broadcast of the Richard Tucker Gala that same year. He also appeared in the PBS broadcast of Lyric Opera of Chicago's production of Antony and Cleopatra, and can be heard as the Son in Hugo Weisgall's Six Characters in Search of An Author on New World Records.