Cellist Yo-Yo Ma is a restless soul. When he plays a piece like Schubert’s “Arpeggione” Sonata, which he has no doubt played hundreds of times, you can feel him struggle to take a new look at each phrase and gesture, each dynamic shading, each mood shift — so that the piece can remain fresh not just for the audience but for him. The result is a peculiar mixture of sincerity and weird inwardness, an almost voyeuristically intimate experience in which Schubert’s straightforward idiom gives way to a remote impressionistic universe of gentle whispers and perfumed shadings.

Ma and pianist Kathryn Stott offered a generous, broad-ranging recital to the Harriman-Jewell Series Audience on Thursday at the Folly Theater, which was packed to the rafters even at prices topping out at $150. At its best, this two-and-a-half-hour recital showed the full measure of warmth, connectedness and technical control that has made Ma into an internationally revered musical spirit. Franck’s A-major Violin Sonata, which cellists and others sometimes play, brought out his burnished, winning tone and for the most part a refreshingly direct approach. Could it be that, because this piece is not a “normal” part of the cello repertoire, it feels fresher in Ma’s ears?

But at other times, as in the “Arpeggione” finale, the ear grew weary of the constant probing hesitations and teased-out curlicues. Yes, I loved the long-breathed tunefulness of the slow movement. But at times Ma’s effort to play as softly as possible made it difficult for Stott not to drown him; for her part, at times her tone grew so feathery-delicate that it didn’t quite “speak.”

The two threw themselves into Shostakovich’s Sonata, Op, 40, reveling in the morose wailing of the first and third movements — where Ma’s heart-rending, confessional approach at times resulted in a distractingly wide vibrato — and tackling the quicker movements with a fine fierceness. The first half ended in Piazzolla’s Le Grand Tango, whose torchy snap was deftly gauged at first but grew old halfway through — and by the end began to feel like camp.

The second half began with a striking, substantial piece by Brazilian composer Egberto Gismonti, Bodas de Prata & Quatro Cantos, which like the duo’s first encore (Cristal) appears on Ma’s Obrigado Brazil CD. Opening with a beautifully sustained long note that seems to appear out of nowhere, it melds folk-like melodies with Debbusian touches and jazzy, cocktail-piano filigree. In Saint-Saëns’ The Swan offered as a second encore, I liked the way the top note of each of his first two phrases died gently into oblivion. This brief miniature was tender and beautiful in its very simplicity — a sort of quiet unfussiness that I wish I’d heard more of through the evening.