Christmas Love by local Chicago band, Rotary Connection, from their 1968 album Peace.
This song, on the Chicago label, Chess Records, features an unknown female vocalist named Minnie Riperton - who was discovered while working as a receptionist at Chess.
Born and raised in Chicago, Riperton would , of course, go on to have a successful solo career (including her hit, Loving You). Riperton is also famously known as the mother of the comedian actress, Maya Rudolph.
Listen closely for references to Chicago in the lyrics, a commentary on the civil unrest of the time.
I love the psychedelic soul/jazz fusion sound of the entire Peace album, which can be heard in its entirety on Spotify.