All it takes is a moment to change your life. There were several memorable ones in Saturday’s engaging La Jolla Music Society SummerFest concert at Sherwood Auditorium, the second of three programs devoted to the music of Shostakovich.

Those moments weren’t necessarily the most dramatic portions of the program; rather, they were places where for a second you may have caught your breath, and perhaps when you started breathing again, you were a little more present.

Consider Borromeo String Quartet violist Mai Motobuchi. She is the consummate ensemble player. But when it came time for her to solo in the String Quartet No. 8, and that happened several times as Shostakovich seems to have a special affection for the viola, her playing was distinctive, individual, and uncommonly human.

With some violists, you feel as if they are playing a big violin. Motobuchi is an unapologetic violist. Her solo passages, which contributed to a well-shaped, penetrating interpretation by her and her colleagues violinists Nicholas Kitchen and Kristopher Tong and cellist Yeesun Kim, were unforgettable.

Then there’s Clive Greensmith, the former cellist of the highly regarded and now defunct Tokyo String Quartet. He was assigned by SummerFest artistic director Cho-Liang Lin to play the role of Mistislav Rostropovich in the "Seven Verses of Alexander Blok," which Rostropovich helped premier in 1967.

It seemed an odd choice, as Greensmith’s playing is distinguished for its elegance rather than its exuberance. But in the opening “Ophelia’s Song,” a duet with Greensmith and soprano Lyubov Petrova, he made his line soar, and ache, and caress, without histrionics and with an unusual consistency of tone.

What about Russian-trained violinist Dimitry Sitkovetsky, who was also assigned to the "Seven Verses" (taking the role of David Oistrakh)? He had exactly the opposite musical temperament. He plays with a mostly intentional inconsistency of tone, constantly changing it to meet the musical situation.

He and Greensmith didn’t play together until the sixth song, “Secret Signs,” but when they did, they met in the middle, calibrating their sound and approach to each other, and creating their own moment.

And finally there’s pianist Vladimir Feltsman, who completed the ensemble for "Seven Verses" (playing the part Shostakovich had planned for himself). Feltsman was the third pianist on the program (Alan Woo performed in the pleasant if uneventful Piano Trio No. 1 and John Novacek did everything he could, but it wasn’t quite enough, in the still impressive Sonata for Violin and Piano, Opus 134 with Sitkovetsky). And Feltsman was the most successful.

You might think this is a Zen koan, but it’s merely a statement about Feltsman: He can lead without leading, and accompany without accompanying.

He was also the most sensitive of the three pianists to the sound of his instrument. He played with power rather than the percussiveness uncharacteristically shown by Novacek and especially evident with Woo.

With them, you remembered the effort. With Feltsman, his playing was effortless.

He was in the moment.