Philadelphia lays claim to a lot of terrific pianists — strong personalities who either trained here, such as Lang Lang, or who, in the case of Jonathan Biss, live and teach here. No other piano personality, though, is quite like Peter Serkin, who followed his highly individualistic 2017 appearance with the Curtis Institute orchestra with an equally distinctive recital Friday night across the plaza in the Perelman.

All right, it was quirky. Serkin, 71, and a 1964 Curtis graduate, made a lot of odd interpretive choices at the Curtis performance of the Brahms D Minor Piano Concerto that, for me, added up to some fascinating questioning. Friday night for his Philadelphia Chamber Music Society program he opened with two Mozart works -- the K. 540 Adagio in B Minor and the Piano Sonata in B Flat Major, K. 570.

The Adagio was straightforward enough. But in the sonata, Serkin made many of the same curious interpretive decisions that he did in the Brahms: seemingly random moments of slowing down, or emphasizing for unclear reasons the turn in a phrase. Here is a pianist who likes to rearrange time and space around him, and of course, that is a pianist’s job.

But what worked in Brahms only seemed like overthinking in this Mozart, and often sapped the music of its emotional charge. Why the broadening of the tempo in the last stretch of the first movement? And in the second movement, what was the point of disconnecting the notes of the opening phrase from each other when clearly they wanted to add up to something? Some melodies were as molasses.

Pianist Peter Serkin performing Friday night at the Kimmel Center's Perelman Theater.
Pete Checchia
Pianist Peter Serkin performing Friday night at the Kimmel Center's Perelman Theater.

These quirksome qualities were a somewhat ominous sign for anyone with an eye on the second half of the concert: the Bach Goldberg Variations, BWV 988. But here he was a different pianist. Individualism yielded revelation. Serkin has recorded this piece a handful of times, and his ownership of it is obvious. Yes, the opening “aria” was loose-limbed. But he endowed each variation with a distinct and sometimes surprising character. Virtuosity wasn’t the point (as it can be for some pianists in this work). Serkin used color to wonderful effect: a bone-dry sound in the left hand here, a violent start to a variation there. In various spots he emulated organ or harpsichord. He didn’t shy from emotion, making variations strident, searching, pastoral or fragile.

There is something metaphysical about the Goldberg Variations that Serkin catches — again, in part from his penchant for unmooring the printed note from the limitations of space and time. The piece removes the listener from daily reality. And what better gift? Serkin heightened the sense of yearning in the introspective 15th variation, ending it with a series of notes that seemed to veer off into the stars.