Two tribute albums to famed singers are nominated for best traditional pop vocal album at the 64th annual Grammy AwardsWillie Nelson’s That’s Life, which is the ninth tribute to Frank Sinatra to be nominated in this category, and Ledisi’s Ledisi Sings Nina, the first tribute to Nina Simone to be nominated here.

Sinatra virtually personifies the traditional pop genre, which was built around songs from the Great American Songbook. But Simone, a jazz-styled singer who is nearly as well known for her calls for social justice, isn’t usually thought of in those terms.

So how did a tribute to Simone wind up in the traditional pop category?

Ledisi won her first Grammy in March for best traditional R&B performance for “Anything for You,” a track from her 2020 album The Wild Card, but the Grammys don’t have a traditional R&B album category. The Grammy screening committee, which makes the final determination of where albums land, had to choose between placing the album in best traditional pop vocal album or best R&B album, where Simone would have competed with the likes of Jon Batiste, H.E.R. and Jazmine Sullivan.

The Grammys have, in recent years, been trying to expand the notion of what traditional pop entails. Here’s the current guideline: “This category is for performances of a type and style of song that cannot properly be intermingled with present forms of pop music. This includes older forms of traditional pop such as the Great American Songbook, created by the Broadway, Hollywood and Tin Pan Alley songwriters of the period between the [1920s] and the end of World War II, as well as cabaret/musical theater-style songs and previous forms of contemporary pop. This would also include contemporary pop songs performed in traditional pop style – the term ‘traditional’ being a reference, equally, to the style of the composition, vocal styling and the instrumental arrangement, without regard to the age of the material.”

Simone is the ninth singer to be the subject of a tribute that received a nod for best traditional pop vocal album. The others, in addition to Sinatra, are Nat King Cole and Judy Garland, each of whom have been the subject of two nominated albums; and Fred Astaire, Billie Holiday, Tony Bennett, Rosemary Clooney and Peggy Lee, each of whom have been saluted with one nominated album.

Simone, who died in 2003 at age 70, never won a Grammy in competition. She was nominated just twice, in both cases for best R&B vocal performance, female. She was nominated in 1967 (the category’s first year) for “(You’ll) Go to Hell” and in 1970 for her album Black Gold. She lost in both cases to Aretha Franklin, whose eight-year lock on the award from 1967-74 helped clinch her title as the Queen of Soul.

Simone was awarded a lifetime achievement award from the Recording Academy in 2017. Two of her recordings have been inducted into the Grammy Hall of Fame, which functions as a second chance for the Grammys to salute worthy recordings. Simone has been recognized for “I Loves You, Porgy” from Show Boat (recorded in 1959) and “To Be Young, Gifted and Black” (recorded in 1969). Both songs reached the top 10 on Billboard’s principal R&B chart, now called Hot R&B/Hip-Hop Songs.

Voting members of the Recording Academy have one more week to cast their ballots. Final-round voting closes on Wednesday, Jan. 3, 2022, at 6 p.m. PT. The Grammy telecast is set for Jan. 31.

Ledisi Sings Nina, which features Metropole Orkest conducted by Jules Buckley, appears to have little chance of winning for best traditional pop vocal album. Bennett and Lady Gaga’s Love for Sale is the clear favorite to win in the category. In addition to its nomination here, it is up for album of the year. This would be Bennett’s 14th win in this category, Gaga’s second. The two stars won seven years ago for their previous collab, Cheek to Cheek.

The other nominees in the category — besides Nelson’s aforementioned That’s Life — are Norah Jones’Til We Meet Again (Live) and a pair of holiday albums, Tori Kelly’s A Tori Kelly Christmas and Dolly Parton’s A Holly Dolly Christmas.