When the Portland Conservatory of Music was founded in 1995, it immediately established a series of free midday concerts at the First Parish Unitarian Universalist Church. It was a smart move: Recitals by the conservatory’s faculty show off the school itself. Student concerts do that too, while giving young players much needed experience performing before the public. And listeners can hear free performances of a broad range of repertory, played by both experienced musicians and promising students, and still have enough of their lunch hour left to grab a quick bite.

The pianist Diane Walsh opened the 20th season of the Noonday Concert series on Oct. 8 with a 40-minute program that included Bach’s Partita No. 4 in D (BWV 828) and William Bolcom’s “Graceful Ghost Rag.” Walsh was for many years a mainstay of the concert world in New York, with frequent appearances as a soloist and chamber player, and a stint on Broadway, where she was both the music director and on-stage pianist in Moisés Kaufman’s “33 Variations,” a meditation on Beethoven’s “Diabelli Variations” that starred Jane Fonda. Walsh moved to Portland last year and now teaches at Colby College.

Pianists who play Bach’s harpsichord music on the modern piano have a range of interpretive options. Some find ways of alluding to the harpsichord’s needle-sharp articulation without jettisoning the piano’s flexibility. Others play the music as if it were actually written for the piano, with all the dynamic freedom the piano allows.

Walsh’s rendering of the Partita – a work included on her most recent recording, an all-Bach set – draws on both those possibilities, but aims at a different target. Her deference to the harpsichord was evident in her crisp, stylish ornamentation, and with phrasing that had the elegance that harpsichordists command almost as a birthright. You could not accuse her of going overboard with pianistic dynamics alien to the older instrument. Yet the impression she created in her stately, warm-toned performance of the Ouverture, and which she sustained throughout the Partita, was that she regards neither the harpsichord nor the piano as fully adequate for this music.

Instead, her sound, gestures and coloration suggested that she thinks of the Partita in orchestral terms, and the most winning aspect of her performance was that she was able to create the illusion of orchestral heft while sacrificing nothing of the transparency that Bach’s counterpoint demands. She also did a fine job of characterizing the individual dance movements, particularly the Allemande, which floated with a gentle sweetness, and the closing Gigue, which was a torrent of energy. The Bolcom required a significant shifting of gears but proved a wonderful concert closer. As both a composer and a pianist, Bolcom is a master of many styles, and his glosses on antique popular styles have always been especially entertaining, mainly because he has the moves down so well. His “Graceful Ghost Rag,” like many works authentically of the ragtime era, has one foot in the salon and the other in a saloon: Syncopations and bluesy turns are offset by a sophisticated but understated humor, and an equally low-key virtuosity. Walsh gave those qualities their due. After the high-flying Bach, it was the perfect way to bring listeners down to earth before sending them back to their daily rounds.

Allan Kozinn is a former music critic and culture writer for The New York Times who lives in Portland. He can be contacted at:

allankozinn@gmail.com

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