Minnie Riperton was a progenitor of what might be termed “hippie soul”… jazzy, psych-inflected, woozy, loose in terms of structure. And Perfect Angel (1974) was her finest moment.

The former singer with Chicago’s experimental rock- soul group Rotary Connection, Riperton had virtually gone AWOL when she was approached to make a solo album – she agreed, as long as Stevie Wonder was at the controls (with assistance on synths/electronics from Wonder associates Malcolm Cecil and Robert Margouleff).

The album’s best-known track is Lovin’ You, a Stateside No.1 and UK No.2 in April 1975: virtually a cappella, with a smattering of instrumentation (no percussion), it’s a showcase for Riperton’s extraordinary five-octave range. It was also a perfect example of how difficult it must have been to market this brilliantly uncategorisable artist.

Was she jazzed-up MOR? Experimental R&B? Elsewhere on this mostly self-penned set there is rock (Reasons), pop (Seeing You This Way) and trippy quiet storm (The Edge Of A Dream, a homage to Martin Luther King). The set is completed with two tracks written by the producer – Perfect Angel and Take A Little Trip – which fi t effortlessly beside Wonder’s own mellifluous synthadelic soul on Fulfillingness’ First Finale.