Never ones to shy away from a quirky concept, prog-funk trio Primus found inspiration in Italian author Ul de Rico's children's book The Rainbow Goblins, and twisted it into something only Primus could create.

The second consecutive album based on a children's story, The Desaturating Seven tells the sonic tale of a septet of greedy, color-eating goblins who terrorize their fictional world by sucking the color out of rainbows.

The album's seven tracks chart their nefarious expedition to the Valley of Rainbows, a paradise untouched by the hungry creatures.

From the creepy introduction "The Valley" to the brief closer "The Ends?," the album is not suited for a casual listen, instead demanding listeners get lost in the weirdness and enjoy the ride.

At points, it's a challenge.

The nearly eight-minute "The Trek" is indeed a trek in itself, while the mostly instrumental "The Dream" tests the limits of patience.

While sometimes silly, if taken as a whole it's a trippy and altogether loony experience.

Highlights include "The Seven," which introduces the titular goblins with an irresistible groove; "The Scheme," the catchy closer for side A that most closely resembles a traditionally pop-structured song; and "The Storm," the album's heaviest moment, marking the Seven's ultimate demise.

Les Claypool's trademark vocals and lurching bass mark this as an unmistakable Primus creation, so fans should appreciate this addition to their collections.

Otherwise, The Desaturating Seven is unlikely to attract new fans.

Typically eccentric, it's an interesting exercise, although nonessential outside the sphere of Primus/Claypool devotees.