Nickolas Ashford (L) and Valerie Simpson arrive at the 2008 Grammy awards held at the Staples Center in Los Angeles

*Usher is set to sing from the Ashford & Simpson catalog for what promises to be a poignant moment in the usually upbeat Grammy nominations prime-time special, set to air live from the Nokia Theatre in Los Angeles on CBS on Nov. 30.

It will be part of a joint tribute to Nick Ashford and Jerry Leiber, and will also feature Mike Stoller, who was Leiber’s longtime writing partner.

The one-hour special in past years usually focused on select nominations and performances from those likely to get those bids. Rihanna, Katy Perry, the Band Perry, Sugarland and Lady Gaga are among those scheduled to participate.

But Ehrlich didn’t want to wait until the Feb. 12 Grammy broadcast to honor the lost legends.

“It felt to me like it might be appropriate to do it at the end of the year, closer to the time of their passing,” he said, according to the Associated Press.

Three months after losing her musical and life partner Ashford, Valerie Simpson acknowledges that she still has a hard time performing any of the classic songs they created together.

“I get a big lump in my throat when I try to sing one of our songs right now,” she tells the AP.

The segment will feature both Simpson and Stoller on separate pianos, as Usher sings. Simpson says she might join in when Usher sings one of their songs, which she expects to be “You’re All I Need to Get By,” but she’s happy not to be doing most of the singing.

“It certainly would make it a lot easier,” she said of Usher performing. “I will be very happy to lean on him.”

She called the death of her husband, with whom she had two daughters, “the most difficult thing I’ve had to do in my life.”

Simpson said his illness came quickly. “Nobody ever really thought of him being sick, and he really wasn’t until the very end,” she said.

The pair were married for 36 years. She said she still goes to their New York City restaurant and club, the Sugar Bar, where they nurtured upcoming talent over the years, and doesn’t rule out writing music on her own.

“I figure the residue of what he leaves here will give me something to carry on with,” she said. “I expect he’ll be whispering in my ear and pointing me in a direction that is right, in time.”