Two years into the pandemic, the two-note opening question of Beethoven’s first symphony sounds more loaded than ever. On Thursday night at the Kennedy Center, it seemed to ask: Is it safe to come out?

Through the end of January, the National Symphony Orchestra will, at long last, embark upon a Beethoven cycle it’s had on and off the books since well before the pandemic (timed to the big guy’s 250th birthday), resuming long-dashed plans to not just perform all nine of his symphonies, but record and release them.

They’ll take on the Fourth Jan. 20-22 and the Third (“Eroica”) Jan. 27-29. The remainder of the symphonies will be performed in the spring. Originally, the Ninth was scheduled as an audacious bookend to the First, but its climactic reliance on a full chorus — in this case, the formidable Washington Chorus — was a no-go amid the latest spike in coronavirus cases. Thus, the Fifth was swapped in.

On Thursday night, omicron had its say but did not dissuade about 1,200 fully vaccinated listeners, who stuffed their puffiest coats between their legs and clutched printouts of nine colorful large-scale artworks created by children’s book author and illustrator Mo Willems to correspond with each of Beethoven’s symphonies. (The exhibition, “Beethoven Symphonies Abstracted,” is on view in the Hall of Nations through March 20.)

The latter half of the cycle series title, “Beethoven and American Masters,” refers to William Grant Still and (D.C. native) George Walker, the two composers chosen to round out each program of the cycle. Thursday night’s performance put Walker’s dazzling, efficient and underheard First Sinfonia at its center.

The famed dissonance of that opening chord of Beethoven’s First — the seventh heard ’round the world — unsettled listeners in their seats when it premiered in Vienna in 1800. It wasn’t the first time a composer woke up and chose violence — the musicologist Joseph Schmidt-Görg points to Haydn; Beethoven’s first teacher, Christian Gottlob Neefe; and even Bach as sources of similarly dissonant inspiration for Beethoven. (And for Ludwig, it wouldn’t be the last — listen to the opening of the overture to 1801′s “The Creatures of Prometheus” and see if it doesn’t serve some evil twin energy.)

But from those weird opening bars, the First fixed itself to history like a hinge between eras, allowing the new century to swing wide open and the gathering breeze of the Romantic era to rush in. The German writer Hermann Kretzschmar once declared it “the final symphonic manifestation of classicism.”

Gianandrea Noseda’s helming of the First on Thursday seemed deeply concerned with capturing the gusto and confidence of the young(ish) Beethoven (he composed this symphony at 29) but also the weight of his inheritance from Haydn and Mozart. (This first symphony even adopts the key — among other likenesses — of Mozart’s last, the “Jupiter” symphony of 1788.) And the orchestra itself was precise and hungry-sounding — a deliberateness that struck me anew.

Noseda maintained cohesion across movements — the scholar Robert Phillip noted that the First is composed “as if one cast is acting out different scenes” — but here and there zoomed in, italicized certain passages, uncovered arresting surprises and minor revelations. The whimsy of its kinetic minuet (pivotal not least to the symphony but to the future of third movements at large) carried over into an energetic finale that built from the violins and spread outward like a wildfire.

Walker makes an inspired counterpart and counterpoint to Beethoven — especially in the context of their first symphonies. In a phone call earlier this week, Noseda pointed to the audacity evident in the openings of each of their Firsts — the way they seize attention and announce their confidence without tipping their respective hands. Both composers excelled with what Schmidt-Görg identified in Beethoven’s First as “a veiling of tonality.”

The two-movement “Sinfonia No. 1” opens with a short sharp shock, as though we’ve entered a catastrophe in progress (it was composed in 1984, so that checks out). Tension holds this symphony together like a suspension bridge — horns and woodwinds stretching into tense beams that winnow into near silence, strings awakening like dawn behind a cityscape, vertiginous towers of horns toppling over. Walker’s early mastery with grand timbral vistas is evident here — an early show of his gathering force — as is the delight he takes in hard contrasts, aggressive chiaroscuro and clangorous intrusions.

It’s worth noting that the NSO plans to incorporate all five of Walker’s symphonies (composed between 1984 and 2016, two years before his death) into the series, making this a de facto (and welcome) Walker cycle to boot.

Post-intermission, Noseda didn’t even wait for the applause to die before pouncing from the podium into the (surprisingly brisk, borderline brusque) opening four-note how-do-you-do motif of the Fifth.

This was the best I’ve heard the NSO — tight and assiduous, but also brimming with personality. The andante movement sounded fresh and full, with especially lovely play across the woodwinds throughout. Bobbing heads dotted the audience through the scherzo, its pizzicato stretch particularly beguiling.

Do I report the gasps of shock I heard throughout this performance of a symphony that everyone already knows? I do. Perhaps the biggest surprise of the NSO’s Fifth is just how full of surprises it was. If there was a question as to why the world needs another recorded Beethoven cycle, Noseda gamely offered the first few notes of an answer.

And if there was a subtext (beyond sequential fidelity) to programming the First first, it may be as simple as the tension that fascinated the 18th century writer Sir George Grove: “A composition professing to be in the key of C begins with a discord in the key of F and by the third bar lands us in G.”

That is, our uncertainties won’t always resolve the way we expect them to, and sometimes that’s for the best.

Beethoven & American Masters: George Walker & Beethoven’s First & Fifth Symphonies repeats at the Kennedy Center on Jan. 15 and 16. More information at kennedy-center.org.