Willie Nelson and Waddy Wachtel/ Photo by Chris Pizzello/ Invision/AP

Willie Nelson and Waddy Wachtel/ Photo by Chris Pizzello/ Invision/AP

Los Angeles -- Melissa Etheridge ripping on lead guitar on “My Guitar Gently Weeps.” Aloe Blacc singing “We Shall Overcome.” Walk the Moon rocking out to “Gimme Shelter” with Deborah Cox.

Sometimes the true test of talent is to see a performer outside of their comfort zone. Not in the context of their own well-rehearsed show but maybe without a safety net.

Such was the case at Lean on Me: a Celebration of Music and Philanthropy, presented by the Grammy Foundation Thursday at the Wilshire Ebell Theatre in Los Angeles.

Yes, after a speech by George Harrison’s widow Olivia, Etheridge played lead guitar on the aforementioned Harrison classic while Blacc handled lead vocals.  Etheridge also sang her Oscar-winning “I Need to Wake Up” as well as the night’s theme song, “Lean on Me,” with a rasp that was borderline Dylanesque.

Walk the Moon covered the Killers and the Stones. Lindsey Stirling, the violinist who dances like a ballerina while she plays, interpreted “We Are the World.” Plain White T’s provided irony by singing “True Colors," the Cyndi Lauper classic.

There were video salutes to the Concert for Bangladesh, Live Aid, MusiCares (Grammys’ charity for musicians) and Farm Aid (which begged for editing).

John Mellencamp told a story about being 40 years old and laying in bed with his grandmother who lived to 100, and then sang a new song she inspired. Backed by a house band that included guitarist Waddy Wachtel and organist Rami Jaffe, Willie Nelson delivered a song of determination, “We Don’t Run,” and a song that describes his lifestyle, “On the Road Again.”

Despite those two philanthropic heavy hitters performing, the highlight was unquestionably Robin Thicke, whose career and personal life have been in the dumps of late. Dueting with gospel star Erica Campbell of Mary Mary, he tore it up on Stevie Wonder’s “Higher Ground.” It was a perfect anthem for the evening.