Harriet Tubman is one of the great bands of our age, first and foremost because it challenges any received wisdom over the character, range and purpose of electric music or ‘power trio’ traditions. Drummer JT Lewis, bassist Melvin Gibbs and guitarist Brandon Ross have done what few others manage as creators of music borne of an early jazz-rock vocabulary that absorbs and reflects the advent of dub, hip-hop and ambient techno without just skimming the surface of these vocabularies. There's such conceptual substance in the songs, so that the darkness-coldness-hardness quotient of these machine-based genres can be clearly felt in the performance as well as the sonic canvas fashioned by the players, yet it doesn't suck the soul out of the music. In other words, the way Lewis works his kick rivals a digital beat-maker's in bulk and concision without succumbing to rigidity, Gibbs' patterning imbues menace as well as momentum to all things pentatonic, and Ross has a 21st-century tonal palette, as well as skilful phrasing. Producer Scotty Hard, who has worked so effectively with other forward-thinking artists over the years, deserves a black ark's worth of credit here but the HT-ers, modernist as their sensibilities are, still know the best way to broach a subject as important as the ‘Green Book’ is by way of the blues. The band set a high creative bar with 2017's wondrous Araminta, but this is a dazzling follow-up, a fearless record that shows the deep roots of African-American music, the raw materials of drums, strings and the equipment of the day, are by no means static in the hands of whosoever dares to jump over the edge of a cliff with a commitment to soar.