A duet usually suggests two voices in a room, trading glances between takes. Plenty of famous ones didn’t happen that way. Sometimes the singers were decades apart, and sometimes they were simply in different cities.
These four recordings show how a shared song can be built across time and distance. Each is a little different in method, and each worked well enough to be remembered.
Natalie Cole and Nat King Cole, “Unforgettable”

Nat King Cole first recorded “Unforgettable” in 1951, and he died in 1965. In 1991, his daughter Natalie released a new version on her album Unforgettable… with Love. It blended his original vocal with her own, so the two could sing together even though he was long gone.
The song was a major success. It won the Grammy for Record of the Year, and the album also took home Album of the Year. Producer David Foster was closely tied to the project, and the track is still one of the best known examples of a duet across generations.
Frank Sinatra and His Guests on “Duets”

Frank Sinatra’s 1993 album Duets paired him with a long list of stars, including Tony Bennett, Barbra Streisand and Aretha Franklin. Despite the title, most of the pairings weren’t recorded face to face. Sinatra’s vocals were laid down first, and the guest singers added their parts separately in other studios.
The approach let a busy lineup fit into one project without matching everyone’s calendars. Listeners hear a natural back and forth, though the performances were assembled piece by piece. The album was a big commercial hit and led to a follow up, Duets II, in 1994.
Hank Williams Jr. and Hank Williams Sr., “There’s a Tear in My Beer”

Hank Williams Sr. wrote “There’s a Tear in My Beer” and recorded it in the early 1950s, before his death in 1953. Decades later, his son Hank Williams Jr. recorded a new vocal to sit alongside his father’s original performance. The result was released in 1989 as a true father and son duet, even though they never shared a microphone.
The music video made the idea even more striking. It used technology of the time to place the younger Williams beside archival footage of his father. The release became a landmark country collaboration and earned major recognition within the genre.
Elvis Presley and Martina McBride, “Blue Christmas”

Elvis Presley first recorded “Blue Christmas” in 1957, and the song became a holiday favorite. In 2008, Martina McBride sang with his original vocal on the album Elvis Presley: Christmas Duets. Other artists on that album also sang alongside his archival recordings.
The technique was simple in concept. The original tracks were kept, and new vocals and arrangements were built around them. For McBride, it meant matching phrasing and feel with a singer who could not respond, which is an unusual challenge in a duet.