HARRISON — At a glance, the five programs that the Sebago-Long Lake Music Festival is presenting at Deertrees Theatre here may seem fairly staid. Three of five include works by Beethoven, and music by Haydn, Mozart, Mendelssohn, Brahms and Dvorak make up the lion’s share of the festival’s offerings, with contemporary works cordoned off on a single concert.

But on closer examination, subtleties. The Beethoven works are part of a three-year traversal of the composer’s piano trios, and the other composers are represented largely by works that are hardly warhorses, their composers notwithstanding. Each program also includes a true 19th- or early 20th-century rarity. And one concert takes a thematic approach, presenting works by Jewish composers, among them contemporary scores by Michael White, Paul Schoenfield and Eric Bailen, who is best known hereabouts as one of the festival’s cellists, a position he has held since 1994.

The opening concert of the festival’s 43rd season, on Tuesday evening, drew a nearly full house to Deertrees, a charmingly rustic, 300-seat theater with superb acoustics, and the festival’s musicians, drawn principally from orchestras and chamber groups around the country, played with passion and precision.

The curtain raiser was Haydn’s String Quartet in F (Op. 50, No. 5), one of the six “Prussian” Quartets Haydn composed in 1787. Like so many of Haydn’s works, courtliness and picturesque description exist side by side here: The opening Allegro moderato, and the third and fourth movements (a menuetto and a brisk finale) are studies in the formal elegance and decorative gesture that were the lingua franca of Haydn’s day, yet the second movement, marked Poco adagio, captures an introspective warmth that seems almost to reach a few decades into the 19th century.

The chance to produce a lush, rich tone is always a lure for string players, so it wasn’t surprising that the ensemble – Varty Manouelian and Movses Pogossian, violinists; Laurie Kennedy, violist, and Käthe Jarka, cellist – was at its best in the slow movement. But there was no lack of vigor elsewhere, and apart from a fleeting moment of dicey intonation toward the start of the Menuetto, the performance was beautifully polished.

For novelty seekers, the program’s principal attraction was Max Reger’s Clarinet Quintet (Op. 146), a work completed shortly before his death in 1916. Reger has had some formidable champions – the great pianist Rudolf Serkin among them – but he remains an acquired taste. His music is skillfully wrought, and it tussles with the relationship between tonality and free dissonance that was in the air during his time. But it also has an earnest dryness that can test the patience. The Clarinet Quintet is livelier than many of his scores, though, and clarinetist Carmelo Galante, supported by musicians heard in the Haydn, gave the solo line a shapely, nuanced reading that made a powerful case for the piece.

The program’s highlight, though, was its most familiar work, the Beethoven “Ghost” Trio (Op. 70, No. 1), which ended the evening. It had everything: The outer movements were brisk and zesty, with Stephen Manes, the pianist, creating sharp contours, and Pogossian and Jarka producing a rich, focused tone. The central slow movement, from which the work takes its nickname – a student of Beethoven’s thought it evoked the ghost of Hamlet’s father – was suitably haunting.

The festival continues through Aug. 11 on Tuesday evenings at Deertrees Theatre. Community concerts are planned for July 19 at St. Peter’s Episcopal Church in Bridgton, Aug. 2 at the United Methodist Church on Chebeague Island, and Aug. 9 at Deertrees.

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

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