The band UFO was originally the house band providing the incidental music for the Gerry Anderson TV series of the same name. He had originally wanted The Shadows, continuing on from their appearance in Thunderbirds, but his desired musical director, Joe Meek, had passed away by that point, so he shelved that idea.
Later, UFO TV star Ed Bishop, living in a village in rural England, teamed up with David Soul, who was living a couple of villages over in a smooth R&B band called Soul to Soul, a triple pun on the name Bishop, Soul, and the genre Soul. After going on hiatus and many personnel changes it became the band Soul II Soul (I.e. version two of the band) that we know and love today.
(Trivia... They really did live near each other)