Smith was best known as the wife and "straight guy" performing partner of Louis Prima, recording several albums with him while they were married from 1953-1961. She would generally sing her parts of their duets more or less deadpan while Prima went on one of his trademark manic performance schticks. Smith also recorded solo records during this time, as Prima had told Capitol Records that if they wanted to sign him, they had to sign her as well. Perhaps as a change of pace from Prima, Smith focused more on ballads and contemplative songs in her Capitol releases, although she did throw some swinging into a tune here and there. And working with arrangment/conducting aces Nelson Riddle and Billy May made sure her voice had all the foundation it needed for whatever she wanted to do with a song.
Following her divorce from Prima, Smith continued recording and some touring work -- including 1965's Keely Smith Sings the John Lennon/Paul McCartney Songbook, another piece of evidence that part of the Lennon-McCartney genius was marrying pop standard songwriting sensibilities to Chuck Berry riffs. She cut back on her performing and recording, focusing mostly on her family.
During the "oughts," Smith recorded and released a couple of compilation albums of some of the standards she had performed earlier as well as some she hadn't recorded before. The Swing, Swing, Swing collection in 2000 showcased exactly what the title promised, a high-energy dance party that ranged from pop standards to a couple of early rock numbers like the Lieber/Stoller Kansas City. In 2001, she released Keely Sings Sinatra, a collection of Frank's songs she'd actually recorded back for his last birthday in 1997-98. A longtime Sinatra friend, Smith held the release for awhile because she didn't want to be a part of the Sinatramania that followed Frank's death. She tackles Sinatra signatures like New York, New York and My Way with energy, phrasing and sincerity that shows why fellow Rat Packers like Dean Martin and Sammy Davis, Jr. called her "the female Sinatra." The 2002 Keely Swings Basie Style...With Strings sets some standards as well as some newer songs in Basie-esque arrangements and lets Smith use her skills and familiarity with the originator of those arrangements to create something that might very well have had the count tapping along happily.
Some YouTube videos show that even as of four or five years ago Smith had lost little of her vocal power and energy. Which means that whoever leads the birthday singing had best be in fine form unless they want to be outshone by the honoree.