'Angel Song' is among the apexes of the label's catalogue, uniting four master improvisers - each with a unique artistic identity - in an intimate, drummer-less quartet session. Kenny Wheeler is the composer of the nine hauntingly lyrical chamber-elaborations and endows them with his singular timbre on flugelhorn and trumpet in expressive melodic exchanges with alto saxophonist Lee Konitz. Dave Holland's bass-foundation is as compelling as ever, giving Bill Frisell all the freedom for harmony-encompassing improvisation.