Adam Lambert has had ample opportunity to show off his rocker edge, his crooner side and his theatrical chops this season on "American Idol." But thanks to show co-creator Simon Fuller, on Tuesday night's (May 19) final performance episode, the Los Angeles native got to dip his toes into some old-fashioned soul on a night when he was making his final bid to America.

Fuller's choice of Sam Cooke's 1964 civil-rights anthem "A Change Is Gonna Come" — paired with his equally poignant pick for Kris Allen, Marvin Gaye's "What's Going On" — allowed Lambert to show his more restrained side.

(See what Jim Cantiello had to say about the night in his "American Idol" live blog.)

The tune, recently sung at the "We Are One" inaugural concert on the steps of the Lincoln Memorial during President Barack Obama's inauguration weekend by Jon Bon Jovi and soul singer Bettye LaVette, was written and recorded in 1963 and released shortly after Cooke's death in late 1964.

Greatly moved by the emotion in Bob Dylan's 1963 protest song "Blowin' in the Wind" and its message of change, Cooke sat down to write the tune after speaking to some sit-in demonstrators in Durham, North Carolina, following one of his concerts.

It was a departure from the more mainstream ballads and dance tunes Cooke had built his reputation on ("Twistin' the Night Away," "You Send Me"). The song was inspired by the accidental drowning of Cooke's 18-month-old son in June 1963 and the disturbing-the-peace arrest of the singer and his band in October of that year for trying to check into a "whites only" motel in Shreveport, Louisiana, with the latter forming the basis for the song's moving third verse.

The song, chosen in 2007 by the Library of Congress to join the National Recording Registry and voted the #12 Greatest Song of All Time by Rolling Stone magazine in 2005, is a throwback to Cooke's gospel roots, and it features the aching final couplet alluding to his son's death: "There have been times that I thought I couldn't last for long/ But now I think I'm able to carry on/ It's been a long time coming, but I know a change is gonna come."

It was included on the last studio album released in Cooke's lifetime, Ain't That Good News, but his label didn't release it as a single, relegating it to the B-side of the more mainstream dance tune "Shake." The tune was quickly adopted as an anthem for the civil-rights struggle, though, and eventually became a minor top 40 hit. Cooke did not live to see the song enter the public consciousness, as he was killed at a Los Angeles hotel by the building's owner in December 1964.

In addition to the version at the Obama inauguration, the song has been covered by hundreds of artists, including Dylan, Aretha Franklin, Seal, the Fugees, Cold War Kids and the Arcade Fire. It's been sampled by a number of rappers, including Lil Wayne, Ja Rule and Ghostface Killah. Obama also made reference to the song's refrain after winning the 2008 election, telling the crowd gathered in Chicago's Grant Park, "It's been a long time coming, but tonight, change has come to America."

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