E-Mail This Article to a Friend Conjunctions A day of John Harbison BY DAVID WEININGER

It’s been a long time since the music of John Harbison was a secret, well kept or otherwise. Known as one of the most fluently inventive composers working today, he turns up on concert programs with dependable frequency, especially around his home turf. But even by those standards, next Sunday, April 18, is notable: Harbison’s works will feature in three concerts that day. Even the composer is impressed. "Well, that is an amazing conjunction," he says over the phone from Wisconsin.

Sunday’s Harbison crawl starts at Jordan Hall, where the Boston Symphony Chamber Players will play his "Six American Painters," along with works by Brahms. Inspired by a series of paintings at the Metropolitan Museum of Art, Harbison wrote the piece in 2000 for flute and string trio. Soon after completing it, he rewrote the flute part for oboe and made more substantial revisions to the work. "I took out one of the movements completely and replaced it with another piece. The [Winslow] Homer movement for the flute is gone, and replaced by the [George] Inness, which is a completely different piece." It’s one of the few works Harbison has written from a visual inspiration: "It was very surprising to me, because I don’t think of myself as being on the visual side very developed. You know, I’m working on that." He laughs. "I enjoyed the research [for that piece]. So many pieces have various kinds of background work, and the background work for that piece was just very rewarding."

Later in the evening, three of Harbison’s songs will be on the bill of the Cantata Singers’ Boston Song Marathon. Of particular interest is "The Flute of Interior Time," a setting of the 15th-century Arabic poet Kabir composed in 1992 for the AIDS Quilt Songbook project that originated with baritone William Parker. How does the song appear to him now, removed from the time and circumstances that brought it forth?

"It’s an interesting question. I think I was aware at the time of wanting to choose a text which, while I felt it was connected in a very broad way to the occasion and the issues, was also . . . let’s just say more image-oriented, less specific." While many of the contributions addressed the AIDS crisis in painfully autobiographical terms, Harbison thought that "the whole cycle would also benefit from having pieces that were more . . . I guess you would say mystical, which is why I chose the Kabir poem." He toyed with the idea of including it in a larger cycle but has found that "it didn’t fit with anything else that I had or anything that I was considering putting together," he says. "So it remains very much a single piece. It really doesn’t want to amalgamate."

In between, at MIT’s Killian Hall, Emmanuel Music will present another entry in its season-long cycle of concerts devoted to Harbison. The series’ retrospective tone has changed his view of his oeuvre in unexpected ways. "The programs were really designed by Craig [Smith, Emmanuel’s music director], so that the way they’re configured has enabled me to think about the pieces on them in a way that I wouldn’t have if I had been thinking about how to put them together. And that’s been interesting to me on every program. He put pieces on that probably I wouldn’t have seen the need or the reason for, but actually — as often with his programs in general — I got it much more when it happened."

Each concert has had a theme, and this one focuses on Harbison’s teachers and teaching. Works by four of his Boston students — John Halle, Melizza Mazzoli, Pelarin Bacos, and Andrew McPherson — will share the bill with Pound Pieces, by his own principal composition teacher, Roger Sessions. Harbison will also play his own versions of songs by Thelonious Monk, whom he remembers seeing often at the Five Spot in New York. "I like the Monk-Sessions conjunction. They were both incredibly strong influences on me at one time. The common ground is that neither of them are apostles of conventional beauty. Their vocabulary is quite consciously designed not to cultivate that response. And both really want the listener to supply a lot of energy. You really can’t listen to Monk without being a total participant. You can’t put it on in the background."

The chance to participate as a performer in the series has also been a welcome one for him, since he’s become preoccupied lately with the sheer physical side of sound. He mentions an instrument development project his wife, a violinist, is working on with a physicist. Following that study "has gotten me interested in just the pure sound quality of instruments," he says. "I listen to strings very differently than I ever did before. And I play with much more pleasure and interest on my viola than I ever did before — just because of this whole thing of appreciating the amazement of these instruments as physical phenomena of an incredible kind. There’s just a much greater pleasure in making sounds and enjoying them now, because for a long time I used to think that music is so much better than it sounds."

John Harbison gets performed all afternoon on April 18. The Boston Symphony Chamber Players are at Jordan Hall, 30 Gainsborough Street in Boston, at 3 p.m. Tickets are $17 to $30; call (617) 266-1200. The Cantata Singers perform in the Boston Song Marathon at Pickman Hall, 27 Garden Street, at the Longy School of Music in Harvard Square at 7 p.m. Tickets are $15; call (617) 267-6502. Emmanuel Music’s "John Harbison and his World" series continues at Killian Hall, MIT, at 4 p.m. It’s free; call (617) 536-3356.