The music of Leon Kirchner — pugnaciously inventive, straddling past and present — has enlaced itself into Paula Robison’s life for decades. The composer seemed a natural choice when Robison began thinking about commissioning a flute concerto in 1975. She had recently heard his Music for Orchestra, which had knocked her sideways. “I wanted that sound — brass, lots of percussion, the sheen of the string sound,” she said during a recent interview, “and I knew he would be able to finesse it so that the flute would somehow be able to be heard.  “Or at least, I prayed that,” she added with a laugh.  As it turned out, audibility would be the least of her concerns. Compositional delays, the piece’s open-ended nature, and a substantial revision by the composer would all combine to make Kirchner’s Music for Flute and Orchestra a more labyrinthine undertaking than Robison had expected. The odyssey comes full circle on Wednesday, when she will give the first performance of the restored version of the original piece with the NEC Philharmonia under Hugh Wolff.  The process did not start smoothly. The disastrous premiere of Kirchner’s opera “Lily,” around the time he was writing the new piece, likely contributed to a severe case of writer’s block. Robison wasn’t even sure that the concerto would be complete until about a month and half before its October 1978 premiere with the Indianapolis Symphony.  When the piece arrived, she discovered that it had the unmistakable sense of irresolution, questions without answers, that Robison loved in Kirchner’s music. That same elusiveness is, she thinks, inherent in her instrument’s voice. “The flute, it can express the inexpressible. Not like the violin, which speaks from the heart, from the ‘I am now.’ The flute can say ‘What if?’ or ‘Who am I?’ in a way that no other instrument can.  “I was thrilled about the piece,” she went on. “I was also going through labor with it — it was being born as we were playing those first performances.” Kirchner changed his mind several times during rehearsals, and there were also free sections with gnomic instructions: “Establish the percussion landscape before the flute enters,” read one.  Robison played the piece several times in the late ’70s and early ’80s with the conductor Michael Tilson Thomas. Crucially, though, Kirchner’s publisher, Schirmer, refused to pay for the score to be properly engraved. Since a definitive score was never created, a conductor had to work from Kirchner’s increasingly palimpsest-like manuscript, which was impossible without taking the time to decipher all the little notes that had piled up.  She drifted away from it, busy with other new works. Then, in the mid-’90s, Kirchner, having entered a phase of more tonal, accessible writing, decided to revise the piece. “It was lovely,” Robison said of the new version. “But I longed, in the intervening years, for the old one, because the original was full of conflict, it had the brashness of his younger years, and things weren’t resolved. And I loved that about Leon’s music — that it was constantly questioning.”  In 2004, she asked Kirchner, then in failing health, to reconstruct the first version in a definitive edition. He agreed, and though Robison was happy, she knew that the composer would have to be compelled to carry out the work. She remembers standing with Sally Wardwell, Kirchner’s companion after the death of his wife, Gertrude Schoenberg, with rolling pins in the kitchen of their New York apartment, forcing Kirchner to confront the original piece. The process involved discarding the revisions from a decade earlier, as well as finally making clear sense of all the minutiae in the original.  Robison continued to advocate for the piece after a fair copy of the restored version was complete. She and pianist Jeremy Denk planned a flute-and-piano reduction; Kirchner said he wanted to do it himself, then never followed up, a gambit Robison viewed as manipulative. “With people who are openly controlling, at least you know who your adversary is,” she said. “But when people you love very much start to pull strings and jerk you around, it can be very difficult.” At a certain point, she simply had to detach.  Kirchner died in 2009, but Robison never felt a sense of closure with the work she’d midwifed. Finally, in 2013, Schirmer told her that if she could arrange two performances, they would at long last engrave the score properly. Wednesday’s performance at NEC will be the first outing for the original version of Music for Flute and Orchestra since 1982. A second, with the New World Symphony under Thomas, will follow in February.  And yet, Robison said, there’s a sense in which her experience with the piece will never be fully closed, something that seems appropriate to a piece whose musical language is shot through with ambiguity, paths without clear endings.  “Someone once told me a work is never completed, it’s just abandoned,” she said. “Any writer sending the manuscript to the publisher, any artist turning away from the canvas, has many things on their mind that are unresolved. I doubt any composer would say, this is it.  “I think Hugh and I will go into this performance with that in mind,” she continued. “This edition is something printed on paper, that human beings can pick up their instruments and play. And yet what we’re expressing is something so ephemeral, so full of questions and changing colors. To be full of questions. . . that’s part of the human experience, isn’t it?”
Almost four decades after she approached Leon Kirchner to commission a flute concerto, Paula Robison presents the last word on the work’s first version at the New England Conservatory.