Although "Some Velvet Morning" is one of the more famous duets Hazlewood and Sinatra recorded together, it is considered a departure from their usual fare, as it is decidedly less influenced by country and western music. The single peaked at number 26 on the Billboard Hot 100 in January 1968.
In 2003, London's The Daily Telegraph called the song, "One of the strangest, druggiest, most darkly sexual songs ever written - ambitious, beautiful and unforgettable." As with many psychedelic songs, its overall meaning is somewhat obscure. The lyrics consist of the male part describing a mysterious, powerful woman named Phaedra, who "gave [him] life … and ... made it end". The male part alternates with the female part, who identifies herself as Phaedra and speaks over ethereal, twinkling music about beautiful nature imagery and about the secrets held by an unknown collective "us." The rhythm shifts from 4/4 for the male parts to 3/4 for the female parts.
The song has been covered many times, usually as a duet.
In November 2003, music critics working for the British newspaper The Daily Telegraph placed the Sinatra/Hazlewood single at the No. 1 spot in their list of the "50 Best Duets Ever." According to Nathan Rabin: "These two weirdly complementary sides of Hazlewood’s persona unite on 'Some Velvet Morning,' a standout track from Nancy & Lee. On that track, Hazlewood and Sinatra sound like they don’t inhabit the same universe, let alone the same song. Over loping spaghetti-Western guitar, Hazlewood sings of Greek mythology and “some velvet morning when I’m straight,” while Sinatra coos about flowers and daffodils in a stoned haze against a backdrop of bubblegum psychedelia. “Some Velvet Morning” sounds like two songs spliced together by a madman, or an avant-garde short film in song form."