ISO embraces Rachmaninoff on his birthday, filling that out with Sibelius and a newish work

Falling right into place to mark the sesquicentennial birth anniversary of Sergei Rachmaninoff will be

George Li: both nimble and deep-delving

the second Indianapolis Symphony Orchestra performance this weekend of the Russian composer's "Rhapsody on a Theme of Paganini." That's no April Fools' Day joke. It would be a pretty lame one if it were. The repeat will happen at 5:30 p.m. today.

Heard the evening before at Hilbert Circle Theatre came George Li's first performance as an ISO soloist in a work that has always been among the public's favorites by Rachmaninoff.  Calling it a rhapsody might seem to signal a formless exploitation of the Paganini theme, the Italian violinist's 24th caprice for solo violin. But it is in fact a cunning set of variations, whose rhapsodic element is most striking in the way the piece begins, taking an oblique approach to the original. There's also the conspicuous use of the "Dies irae" chant of medieval origin; the melody has found occasional prominence in classical music from Berlioz's Fantastic Symphony (1830) on.

Marianne Williams Tobias' fascinating program note details Rachmaninoff's biographical and occasionally mystical interest in the chant's evocation of Judgment Day and its application to the tug of evil that has long been linked with Paganini as the devil's-bargain secret of his virtuosity. Thus, the work can be heard as both an abstract exercise in wit and structure and a journey according to a lurid scenario.

Li, a 27-year-old with an unusually busy schedule and performance résumé, displayed from the first a zest for the often pointillistic nature of the piano writing. His tone in staccato and rapidly articulated passages was uncommonly rich. His touch was never superficial. Clearly he takes this work seriously from beginning to end. With guest conductor Robert Spano on the podium, the meeting of minds about the score was consistently in play.

Changes in atmosphere were effectively handled: the 17th variation, suspenseful as well as dreamy, made a perfect introduction to the 18th. That contains the ingenious tune the composer concocted by turning the theme upside down and lingering romantically over the result. (Only some shaky, soft trumpet phrases robbed the 17th variation of a little magic.) From the 18th variation through the 24th, all  performers gloried in the brisk virtuosity that Paganini's Opus 1 caprices introduced to the violin universe.

Li responded to the tremendous ovation with several returns to the stage before offering an encore: Liszt's "La Campanella," another inspiration from Paganini. The guest artist's outstanding skill of making rapid playing ring out with no hint of fragility got further exhibition here. As the texture thickened, no fogginess found its way into all the excitement.

The program's main companion, occupying its second half, is Jean Sibelius' Symphony No. 1 in E minor. Both this piece and the Rachmaninoff share an oddity: a short, whispered coda rounding off a bravura finale.

Spano, unencumbered by eloquent gestures, elicited a first-rate performance with a wealth of clear communication to the orchestra. Starting with Sam Rothstein's well-shaped, haunting clarinet solo, Friday's performance was outstanding. Great swells in the strings exerted titanic force seconded by the brass. The string choir also was excellent in the finale's broad melody, which recalls the initial clarinet solo. Jack Brennan's timpani had the requisite punch and rhythmic drive, right through to the fourth movement's climax.

The tenderness of the slow movement yielded in significant ways to a strenuousness that the Finnish composer always exhibited, though the controlled way the movement subsides got full support in Friday's performance. No wonder Sibelius as symphonist was taken by mid-20th-century audiences as  a worthy successor to Beethoven. There is also in Sibelius' maiden voyage a commitment to loading the expressive weight of a symphony on the finale, a Beethoven innovation. Other favorite Sibelius symphonies, particularly the Second and the Fifth, memorably make much of such an emphasis. That weight remained buoyant in the ISO's performance under Spano's sure hand.

A product of Spano's time with the Atlanta Symphony Orchestra encouraging new works by Southern composers opens his two concerts here. Brian Raphael Nabors' "Onward," premiered by the ASO in 2019, the year of its composition, comes with the sort of verbal message that young composers often thrust forward nowadays to show their interest in generating positive responses to the world's messiness. One finds such attempts to win favor in statements by pop and jazz musicians about their new music, too.

I don't want to detach a composer's declaration of values from his actual work, but "Onward" seemed on first hearing Friday a masterly piece of orchestration and expressive focus evolving out of a hushed rhythmic pattern, then encompassing neat, brief solos by the string principals. It's a catchy piece.

There's occasional punctuation by the slapstick, a massive crescendo, then a subsiding episode including what sounded like pitchless flute "breaths" to herald a soft ending.  I take this as Nabors' attempt to sprinkle balm over our troubled souls today — sighs of a relief that may continue to be elusive. But it's worth a shot.