Vasily Petrenko and Paul Lewis – two young men, around 40 years apiece – joined forces at the CSO last week in a program of very mature works. Lewis, who has already gained a reputation as a defining interpreter of Beethoven, played the composer’s last piano concerto, the "Emperor." The 38-year-old Russian conductor followed this alternately sunny and tender work with Rachmaninov’s last orchestral score, the Symphonic Dances. Elgar’s Italian overture, In the South (Alassio), rounded out the program.

Petrenko took to the podium for the Elgar, his manner all Italian holiday. Though the work is essentially a pastoral, it’s not without its curious and intriguing surprises. Far from being all postcard sun (although there is much of that), there’s a rather astonishing middle section that veers to the octatonic, and a prominent viola solo (unfortunately out of tune on this occasion).

At its best, the work can be sumptuously mysterious, but it felt underprepared. The brass section was a little overblown in the first half, and could have used a good deal more warmth in places where it joins the strings to simmer in pastoral color. It didn’t help that Petrenko tends toward a slightly classical, clipped articulation (this was evident in both the Elgar and the Rachmaninov), which broke building momentum more than once. But some of these odd choices were merely symptomatic of a deeper problem. Despite his balletic and often beautiful command of the podium’s space, the dynamic range Petrenko coaxes out of the orchestra is actually quite small, though admittedly he is always fighting the cavernous Symphony Hall. I wonder if consideration of the balcony’s back row prevented him from risking a pianissimo here and there.

The Chicago Symphony Orchestra's sound was steely and oversmooth rather than warm, supple and resonant; it lacked a core. Yet the Symphonic Dances featured some of the sharpest playing of the night, in part because Rachmaninov’s florid contrapuntal writing married beautifully with the orchestra’s strengths, namely precison and manual dexterity. Here, Petrenko’s baton movements became less poetic and more precise, and the results showed. 

If Alassio offered the weakest reading of the night, and the Symphonic Dances the strongest, Lewis’ “Emperor” concerto settled, maddeningly, in between. His strongest suit is by far the sound he is able to produce at the keyboard. Holding his arms stiffly out as if in a straightjacket, the sound that comes out of his piano is dense and rich, as if the instrument were made not of wood but of bronze. A signature moment was the quasi-improvisatory gesture that opens the concerto: Lewis conjures up such a sound here, ringing the instrument’s diapason from bottom to top.

There were further moments of magic, notably in the cadenza, when he produced a gaspingly soft touch. Yet other parts of the concerto were vexingly unfinished, such as the several rapid passages in which an abundance of pedal was deployed clearly to mask rough finger-work. Yet the most disappointing feature of Lewis and Petrenko’s reading was that it was at once a little too flexible to be stately, and too brisk to produce moments of suspension and lingering beauty. This “Emperor”, in other words, lacked both intimacy and spine; it needed both to succeed.