As the subtitle makes clear, the premise of this work is audio-visual. Yet what is even more compelling is the specific theme of Portugese colonialism in Angola, depicted in Super 8 archive footage during the concert that took place prior to the studio session.

Vocalist-composer-narrator Sara Serpa thus addresses the western world's ‘collective shameful past of occupation, exploitation, slave trade, oppression, racism, segregation, violence and abuse’, and her greatest achievement is that all the above phenomena are not conveyed with histrionics or outpourings of anger. In fact, the sustained intensity of Serpa's song cycle stems from the focused containment and understatement of the sound world she has crafted.

The absence of drums and bass enhances the floating introspection of melodies that blur the line between austerity and poignancy, perfectly serving the undercurrent of deep lament that is relevant to such serious subject matter.

Her top notch accompanists, pianist David Virelles, tenor saxophonist Mark Turner and harpist Zeena Parkins, prove to be wholly effective team players because their sense of measure and attention to detail are appropriate on largely slow or mid-tempo material. As for the unique sound of Parkins' tuning forks, it amounts to a beguilingly unplugged electronica, which enhances the arrangements.

Serpa, with her delicate chants, hums and piercing clarity of tone that loosely evokes anybody from Lauren Newton to Norma Winstone, moves seamlessly between scored lines, improvisation and spoken word, to bring sufficient structural variety to what is nonetheless a consistent atmosphere of questioning and resistance. Politically and musically, this is an important, fearless piece of work that should be widely heard.