President Obama sang a few lines of “Sweet Home Chicago” during a tribute to the blues at the White House on Tuesday night. President Obama sang again on Tuesday night, letting loose a few lines of “Sweet Home Chicago” in the finale of a tribute to the blues at the White House. It was the encore to his Apollo Theater snippet of Al Green at a fund-raiser on Jan. 19, and while no one will be suggesting he give up his day job for a pop career, he did fairly well. Breaking news about the arts, coverage of live events, critical reviews, multimedia and more.A sortable calendar of noteworthy cultural events in the New York region, selected by Times critics. President Harry S. Truman playing the piano in 1945, with Lauren Bacall in attendance. President Richard M. Nixon performing in 1969 for Mr. Truman and their wives. Gov. Bill Clinton playing on “The Arsenio Hall Show” in 1992. Mitt Romney singing “America the Beautiful” on a January visit to Florida. Blues singing is part oratory, and after a faltering start on Tuesday, Mr. Obama declaimed his lines with adequate warmth and gusto. He also knew enough not to start into an additional verse. Still, he was better at the Apollo, where he sang the opening of “Let’s Stay Together” in the same key, and on the same notes, as Al Green’s original recording. Did Mr. Obama get lucky, or is he secretly harboring perfect pitch? With his few phrases of song, Mr. Obama joins the list of presidents who have gone public as musicians, from Harry S. Truman’s love of classical piano through Bill Clinton’s tenor saxophone. But there’s risk and reward in any presidential display of musicianship. If every presidential act is symbolic, then showing an interest in music humanizes the chief executive, claiming a connection to culture and emotion. But performing in public — especially in the YouTube era — means that an amateur faces comparison to professionals, while the choice of repertory also gets scrutinized. And should the head of state be taking time away from the job to practice? The repertory for political figures has changed radically over the decades, moving from Eurocentric high culture to American popular culture — or, perhaps, from elitism to the vernacular, as presidents have been demystified, and pollsters ask voters about which candidate they’d prefer to share a beer with. Both Truman and Richard M. Nixon studied classical piano; according to the Truman Library, that president’s favorite composers were Mozart, Beethoven and Chopin, every last one of them a dead European (though he also liked Gershwin). When Nixon sat down to a piano on “The Jack Paar Show” in 1963, he was backed by a small orchestra in a “concerto” based on a tune of his own; he grimaced when he fumbled a few notes. Compare that to a defining moment in Mr. Clinton’s 1992 campaign: when he put on sunglasses, picked up his saxophone and played “Heartbreak Hotel” on “The Arsenio Hall Show,” at once aligning himself with an African-American talk-show host, an Elvis Presley hit, the rock ’n’ roll generation and the retro 1950s cool of shades and yakety sax. (Luckily he got some down-home tone out of the instrument and showed some improvisation too.) Mr. Obama’s very brief forays as a singer have made comfortable choices. He has sung blues and soul standards, vintage and widely beloved music; sales of “Let’s Stay Together” spiked immediately after he sang it. The songs have not only suited his vocal range but also tacitly affirmed his African-American identity in an election year, when every politician seeks to rally his base. In “Dreams From My Father” Mr. Obama wrote, “Pop culture was color-coded, after all, an arcade of images from which you could cop a walk, a talk, a step, a style. I couldn’t croon like Marvin Gaye, but I could learn to dance all the ‘Soul Train’ steps.” But while the president and his wife, Michelle, have broadly embraced American popular culture by presenting a series of musical events at the White House — including tributes to country, Latin music, civil-rights songs and now the blues — Mr. Obama isn’t remaking himself as entertainer in chief. He hasn’t let loose with a full song — only sound bites. That’s sensible; the longer the performance, the more chance there is to veer off-key, as both Hillary Clinton (who made a campaign joke of a video that caught her badly singing along with “The Star-Spangled Banner”)and recently Mitt Romney, who was more earnest than melodious singing “America the Beautiful” in Florida, have discovered on the campaign trail. “Pitchy” is the word used on “American Idol” for performances like those. But the votes Mr. Obama wants to get aren’t going to be counted on “American Idol.” They’re cast on Election Day.