Boris need no introduction — a Japanese trio whose insatiable curiosity has produced, since the 1990s, one of the most teeming discographies in heavy rock. Drone, doom, noise, pop, ambient: the band have explored everything, often within the same record. The title Heavy Rocks, already used in 2002 and then in 2011, designates for them a precise facet of their work: that of riff-driven rock, frank and generous. This third instalment, hailed by the critics (an 80 average across six reviews), extends the tradition.

What the press retain is the contagious glee of the whole. Boris seek here neither conceptual depth nor radical experimentation: they stack stoner riffs, saturated fuzz, punk surges and psychedelic soars in a joyful, fully assumed disorder. It is a record of immediate pleasure.

Musically, the thick, colourful production showcases this wealth of textures. The tracks move from the stoner bulldozer to the drifting ballad, from noise fury to pop melody, with an ease that attests to a total command of the codes. Boris are having fun, and it shows.

The flip side of this eclecticism is a certain lack of unity: Heavy Rocks plays as an anthology of facets more than as a coherent work, and not all the tracks reach the same peak. One picks at it as much as one listens straight through.

Verdict: 8/10. A generous, playful, pleasantly messy record reminding us that Boris have lost none of their hunger or their freedom. The riff as a party.