The album 'The Duke Ellington Songbook Vol. 1' by Sarah Vaughan was released in 1979, but there is no verified information about its recording, producer, or record label in reliable sources.
It is speculated that this record may have been a compilation of previous Vaughan recordings performing compositions by Duke Ellington, although there is no official confirmation.
The lack of precise data makes this album difficult to document; it does not appear in Vaughan's main discographies or in the catalogs of the best-known labels.