Kamasi Washington’s runaway success has exploded the conventional wisdom that jazz can only cross over when it’s smoothed out or fused with contemporary genres. Associations with Kendrick Lamar and Flying Lotus have certainly helped the Los Angeles-based saxophonist reach new audiences, but his own music makes few explicit nods to hip-hop. In essence, Washington’s music is part of the soul jazz continuum, absorbing elements of spiritual jazz, Latin, fusion and R&B. It might not be formally radical, but the tunes are irresistible, and Washington and his band The Next Step have a winning charisma.

Heaven and Earth builds on the sound established on Washington’s 2015 debut studio album The Epic. Disc one, Earth, opens with a bold new arrangement of the theme from the Bruce Lee classic Fists of Fury. Washington embraces the daft but righteous spirit of the original, stacking choral fanfares over hot Latin rhythms and outrageous bongo fills. It’s winningly audacious, but as the music gathers momentum via a series of powerful horn solos, Washington’s serious intent becomes clear. The original lyrics – “I use hands to hold my fellow man/ I use hands to help with what I can… When I face unjust injury/ then I will change my hands into fists of fury.” – are delivered simultaneously by Patrice Quinn and Dwight Trible. While Quinn sings with a steely resolve, Trible testifies like a Pentecostal preacher, his voice distorted to sound like a recording from the Civil Rights era. In the context of police brutality and Trumpian white supremacy, these lines become a forceful expression of Black Power.

The Next Step’s mastery of dynamics and space is all the more apparent on their version of Hub Tones (a piece originally performed by late trumpeter Freddie Hubbard), where Brandon Coleman’s nightclub organ tempers the heat generated by Dontae Winslow’s trumpet. Connections breezes along on a hip West Coast groove, its airy sax and flute theme alternated with striking trombone and synth features. A soul tune in the key of Stevie Wonder, Testify is a showcase for Quinn’s delicious vocals, bejewelled by Coleman’s clavinet. The free blowing introduction to The Invincible Youth hints at the tumult of John Coltrane’s 1966 album Ascension, but out of the chaos emerges an elegant piano and horn melody, buoyed by Thundercat’s fluid bass.

While Earth focuses on consolidating the group sound, the album’s second half Heaven sets its ambitions higher. Space Travellers’ Lullaby is a dreamy venture into sci-fi exotica. Strings glide through a piano starred cosmos, buffeted by celestial choirs and echoplex saxophone. Vi Lua Vi Sol is a curiously appealing hybrid of Daft Punk and Quincy Jones which explores the vocoder’s strange robot soul, while Street Fighter Mas injects g-funk into West Coast jazz via Thundercat’s lubricious bass and Cameron Graves’ wheedling synths. Drummers Tony Austin and Ronald Bruner Jr lay down a low-slung funk beat, while Washington comes in at an angle with waspish triplet licks. In an inspired invocation of the sacred and the profane, the choir comes in over the dirty groove, before Bruner takes it home with a furious burst of junglist polyrhythms.

The gospel undercurrents come to the fore on the final tracks. On Show Us the Way the stately choral refrains and elegant piano voicings recall the sacred music of Duke Ellington and David Axelrod, but it’s shot through with an ecstatic quality. Having made his appeal to the Lord, Washington turns to the people on Will You Sing. A gorgeous piano introduction provides a moment’s reflection, before an athletic drum fill takes us into a squelchy bass and clavinet groove. The piano theme continues, its wistful tonality transformed by the setting into something brightly optimistic. It might sound patronising to talk of Kamasi Washington’s generosity of spirit, but his music gives great pleasure and emotional uplift. No wonder it has resonated so widely.

Stewart Smith