Photo

Mr. Wonder’s voice was bright and true, snaking through the melismas that successive generations of singers have emulated and rising easily through every uplifting key change he had built into the songs. At 64 — he started young — Mr. Wonder showed that his lifelong melding of serious intentions, omnivorous musical sophistication and jubilant execution was utterly sure. He laughingly forgot a lyric, played the wrong harmonica for a moment, sang just enough sour notes to show that he’s human and suffered numerous microphone glitches. It was the first show of a tour. But the concert was a triumph: not a simple nostalgia trip but a return visit to songs and ideas that still matter.

“Songs in the Key of Life” was beloved from the moment it appeared. It won a Grammy as album of the year and is widely cited as a favorite by musicians and pop listeners. In interviews, Mr. Wonder has called it the album he is most happy with. But it’s also a long, sprawling experience: 21 tracks that originally filled two LPs and a four-song EP.

Its songs touch on social ills, individual joys, faith, love, war, music, birth, memories, fears and hopes. One title may sum it up: “Joy Inside My Tears,” a ballad that, when he got to it at Madison Square Garden, had Mr. Wonder pounding the top of his piano with his fist, singing the title again and again with gospelly insistence.

Along with the radio-friendly tracks the album is widely remembered for — “Sir Duke,” “Isn’t She Lovely,” “I Wish,” “Pastime Paradise” — it holds exploratory songs like “Contusion,” a jazz-rock instrumental in tricky shifting meters, and “Black Man,” an anti-racism history lesson in funk.

It also balances hurt and healing; its opening song, the beguiling “Love’s in Need of Love Today,” warns, “The force of evil plans to make you its possession” unless love can conquer hate. The album traverses styles; there are blues, soul, rock, funk, chamber pop, bossa nova, big-band salsa, jazzy ballads, even honky-tonk country (in “Ebony Eyes,” for which Mr. Wonder brought out what he called a “thumbtack piano,” an upright with thumbtacks in its hammers to make each note go plink).

What has held it together, then and now, is Mr. Wonder’s good intentions and boundless musicality. All over the album, he ingeniously meshes syncopated ascending and descending lines, as he did in the upbeat “Sir Duke,” the doleful “Pastime Paradise” and the kinetic “I Wish.”

Onstage, he let the best riffs stretch out, savoring the danceable constructions he had set in motion decades ago, as the audience members, many of whom were around for the original album release, stood and shimmied. Now and then, backup singers — including India.Arie, who came and went in multiple regal costumes — took over verses that Mr. Wonder had originally sung. But he was always there to chime back in on higher, more difficult variations.

Mr. Wonder was voluble between songs, joking about tabloid reports that he dismissed as rumors but also doing some preaching. He advocated more accessibility worldwide for the disabled, and he called for better gun control, pointing to a family in the audience that lost a daughter in the massacre at Sandy Hook Elementary School in Newtown, Conn. In what seemed like a scripted moment, he said: “I challenge America, I challenge the world, to let hatred go, to let racism go. To respect every single man as if they were your brother, every woman as if they were your sister, every single child as if they were your child.” He continued, “This is the only way we will win as a nation, as a world.”

For an encore, he played one song that wasn’t on “Songs in the Key of Life”: his hit “Superstition,” bolstered by the six-member horn section that was part of the band, which also included a string section and multiple percussionists, keyboardists and guitarists. It wasn’t too different from the rest of the concert: a great riff, a kinetic beat and a warning everyone could dance to, this one about dogma versus rationality. “Superstition ain’t the way!” the arena sang along.