(Credit: Dario Acosta) The Juilliard Orchestra is set to perform Mahler’s Symphony No. 3 on April 14. The orchestra will perform the symphony for the first time in 20 years and will return to Carnegie Hall for its annual performance. David Robertson, Juilliard’s director of conducting studies, will lead the orchestra with soloist mezzo-soprano Samantha Hankey, the Preparatory Division Chorus—composed {…}