Hear Aaron Diehl play ‘Rhapsody in Blue with’ the Philadelphia Orchestra

There’s an entire world of jazz in Aaron Diehl’s playing. The way the pianist reveals that world is particularly mesmerizing in the solo sections of Gershwin’s Rhapsody in Blue, the centerpiece of the Philadelphia Orchestra concert film streaming online starting Thursday.

Diehl has a freedom and playfulness that make you hear the piece anew throughout. But it’s in the solo-piano parts that his thinking grows expansive. With a highly improvisatory approach, he makes the case that jazz is not one style or genre but many, gliding gorgeously among decades of artistic influences.

Diehl’s agile mind is just one of several aspects of this performance that makes it so good. In this program, the orchestra plays the original 1924 jazz-band version of Rhapsody in Blue orchestrated by Ferde Grofé, and for all of the grandeur of the traditional full-orchestra version, this one is a lot more fun. It starts with the familiar clarinet smears, played here by Ricardo Morales, which end by dovetailing beautifully with the muted timbre of David Bilger’s trumpet.

What’s fascinating from there is that even for reduced forces, the ensemble does not want for power or mass. The big moments are as big as ever. But the differences shift the sound universe from concert hall to nightclub — more Paul Whiteman than Eugene Ormandy. The drum set adds punch, and saxes layer on the cool. A banjo player is visible, though it would have been nice if sound engineers had heightened the instrument’s presence.

It’s probably true that not a lot of Philadelphia Orchestra music directors would have felt at home in this repertoire, but Yannick Nézet-Séguin does a wonderful job of regulating the tension and release — the optimism and euphoria at one end of the dramatic spectrum, and sweetness and intimacy at the other.

The entire Digital Stage program this week straddles genres and periods. Duke Ellington’s dreamy “Solitude” is made even more dreamy in Morton Gould’s harp- and celesta-laced orchestration. It’s a brief work — just over three minutes long — but powerful in its mood-setting spell.

Considering the Ellington and Gershwin together, you have to be struck by the role of the often unsung orchestrator. Neither piece would have quite the same impact were it not for being swaddled in the luxurious cloths of Grofé and Gould.

Did Stravinsky do the same for Pergolesi? Pulcinella draws on music Stravinsky thought was penned by Pergolesi but is now believed to be a mix of Italian composers. The result, in any case, is a pleasure, and a piquant one here in the suite from the ballet.

The solo work is especially compelling. Trombonist Nitzan Haroz has the perfect mix of swagger and polish, and having a piece in which oboists Jonathan Blumenfeld and Philippe Tondre are playing side by side gives a glimpse at the differences in their respective schools of playing. The value of having the camera’s eye inside the ensemble was especially evident in the lovely wind variations of the “Gavotta” section, where you focus on who was doing what. Oddly, the pandemic has in some ways drawn us closer to the orchestra.

The Philadelphia Orchestra’s program of works by Ellington, Gershwin, and Stravinsky streams April 15 at 8 p.m. through April 22 at 11 p.m. Tickets are $15 or $17. philorch.org.