Last week in Cleveland, the music played at the Republican National Convention often seemed at odds with the messages coming from the stage – sometimes to the explicit distress of the musicians. By Sunday evening, with Donald Trump's event over and with Hillary Clinton's about to begin, an eclectic group of musicians had assembled on John Oliver's show Last Week Tonight for a skit with a bipartisan message: Their work shouldn't be used in the political realm. The motley crew included Usher, Cyndi Lauper, John Mellencamp, Josh Groban, Sheryl Crow, Michael Bolton, Nancy and Ann Wilson of Heart and Dan Reynolds of Imagine Dragons, all singing a "hands off" anthem: "Don't use our song / 'Cause you used it wrong / It might seem appealing / But you're just stealing."

By contrast, at the Democratic National Convention in Philadelphia this week, American musicians and entertainers — by and large a liberal bunch, it must be said — lined up to get behind the nominee. Some even became actors in this particular piece of political theater, taking on the explicit mission of bringing a divided party closer together.

Philadelphia's own Boyz II Men kicked things off on Monday night, pulling out its 25-year-old debut single "Motownphilly" to welcome the delegates. "Not too hard! Not too soft!" three of the group's original members sang in a smooth performance that showcased them as hype men for their hometown; the only messaging was the one implied by their mere presence at the DNC. Thursday night featured Sheila E. at her drum set, playing with three Latin percussionists including her father, Pete Escovedo. Like Boyz II Men, E. didn't speak from the stage at all, though she has made public statements about the importance of this election to Latino and African-American voters.

At least one vocalist was invited to the DNC to do more than sing. Pop star and actress Demi Lovato, who has wrestled quite publicly with mental health and addiction issues, took the mic on Monday night to speak about mental health advocacy and urge politicians to support laws that make care more accessible, before launching into her hit "Confident."

Some performers hinted at a message of reconciliation — not between the red/blue political divide in the U.S., but rather between supporters of Hillary Clinton and of Bernie Sanders. Carole King was one; after singing arguably the biggest hit from her vast catalog, "You've Got a Friend," she riffed: "Hillary's got so many friends! Bernie too! And all of us together!"

Other artists stuck to paeans to love and fellowship — which, during any other political season, would probably have been received as feel-good and wholly generic missives. But in this strange election year, they carried a surprisingly potent punch. On Wednesday night, a busful of Broadway luminaries performed Burt Bacharach and Hal David's "What the World Needs Now Is Love," which many of the same stars recently recorded together as a fundraiser following the mass shooting at the Pulse nightclub in Orlando, Fla. Among the 40-plus voices were Audra McDonald, Idina Menzel, and Ben Vereen — who sported a cap reading "Spiritual Enforcer" — as well as an off-key Rosie Perez, who appeared both self-aware and good-humored about her vocal shortcomings among that all-star lineup. Lenny Kravitz struck a similar note in his performance of "Let Love Rule," which he song with the help of a choir and a Hammond B-3 organ. In case anyone missed his point, Kravitz ended by reiterating: "We gotta let love rule! One God, one planet, one people! And love is the only solution!"

Kravitz brought the same sentiments to an event just across the Delaware River in Camden, N.J., where on Thursday afternoon he joined Lady Gaga and DJ Jazzy Jeff for an invite-only free show for delegates called "Camden Rising" — something of a bid for resurgence by the long-struggling city. Though it wasn't an official DNC event, Gaga didn't miss the opportunity to stay firmly on the Democratic message. Her setlist included progressive staples "This Land Is Your Land," Phil Ochs' "The War Is Over" — and, in perhaps a direct exhortation to the fractured left, The Beatles' "Come Together."

In the entirety of the convention week, the most awkward appeal for harmony came from Paul Simon, who had the thoroughly unenviable task of preceding Bernie Sanders' address on Monday night.

The iconic singer and songwriter was introduced by Senator Al Franken, a Clinton supporter, and comedian Sarah Silverman, a former Sanders supporter; they were lustily heckled. Simon walked onstage right after Silverman said, in obvious exasperation with the crowd, something that became one of the most quoted lines of the night: "To the Bernie-or-bust people: You're being ridiculous."

Even so, the energy appeared to shift when the artist walked out onstage; those rowdy delegates seemed primed to give this musical legend his proper due. But what would Simon sing? His choice was freighted with meaning, especially considering that Simon & Garfunkel's "America" had already become closely identified with the Sanders campaign.

As soon as the pianist played the opening bar of his selection, it was immediately obvious what Simon was going for: He had selected "Bridge Over Troubled Water." The metaphor was blindingly clear: Simon would be the delegates' bridge to harmony. And maybe — just maybe — Simon's former partner Art Garfunkel, who originally sang this iconic song, would also materialize onstage. What a model of reconciliation for the Sanders and Clinton camps that could be!

And yet, the performance backfired. Maybe the key was just a hair too high for comfort, but Simon sounded uncharacteristically frail and unsettled. Garfunkel was nowhere to be found. And some of the crowd continued to audibly jeer Clinton and her supporters from that night well into Thursday evening.

Still, as the week progressed, the live performances grew more buoyant — especially on the part of some female artists keen to the significance of a woman being nominated for president by a major party. Andra Day sang "Rise Up" with a marching drumline, and Alicia Keys dedicated her performance of "Superwoman" to the Mothers of the Movement "and all mothers who have lost their sons or daughters to senseless violence." Keys also made a bid for unity between the Sanders and Clinton camps before launching into her song "In Common."

Some of Clinton's hallmark anthems from the primary season were put back on heavy rotation this week. Rachel Platten's "Fight Song," which has been deployed by Clinton's campaign for some time now, was the music that ushered the candidate to the stage for her acceptance speech Thursday night; it was also the basis for a video produced by actress Elizabeth Banks that had the feel of a viral effort and featured an eclectic array of performers, including Platten herself, as well as several members of the cast of the movie Pitch Perfect, opera star Renée Fleming, Idina Menzel (again) and Australian-born hitmaker Sia.

The other mainstay of this week in Philadelphia was the songbook of Katy Perry — another staunch Clinton supporter since before the Iowa caucus. Before she performed her hits "Rise" and "Roar" last night, Perry had an exhortation not so much for the crowd in Philadelphia, but for those watching from their screens at home. "On Nov. 8," Perry said, "you'll be just as powerful as any NRA lobbyist. You'll have as much say as any billionaire. Or you can just cancel out your weird cousin's vote, if you like."

Copyright 2016 NPR. To see more, visit http://www.npr.org/.