From the 2010s onward, Yann Tiersen's music reflected just how important his roots were to him. Though he took a brief break with 2019's Portrait -- itself a celebration of his decades-long career -- he dedicated several albums to chronicling his homeland of Ushant, a small island off the west coast of Brittany in the Celtic Sea. On 2016's Eusa, his delicate piano compositions sketched out a musical map of the island, a concept he expands on with Kerber. Named for a chapel on Ushant and inspired by the landscape surrounding Tiersen's home, its pieces were also originally written on piano (and as with Eusa, Tiersen made Kerber's compositions available as sheet music), but the composer and producer Gareth Jones restructured them with intricately crafted samples and electronic processing in Tiersen's Ushant studio, the Eskal. The results feel like a mingling of the past, present, and future of Ushant and of his music. Aside from the obvious connection to Eusa, Kerber's washes of sound hark back to ∞ (Infinity)'s luminous atmospheres, and the way Tiersen and Jones weave together acoustic and electronic elements showcases the composer's refined melodies. Ricocheting textures and hazy ambiences branch off hopefully from "Kerlann"'s deceptively simple piano part, while shimmering contrails float after "Ker Yegu"'s sunny melody and counterpoint. These artfully layered sounds give the impression of multiple histories and memories piled atop each other on pieces such as "Ar Maner Kozh," where fluttering synth bass, reverberating piano, and dewy electronics conjure an enveloping yet hard to classify mood. Kerber's distinct emotional states highlight every facet of Tiersen's love for Ushant, whether it's the unabashed sweetness of "Kerdrall" or the more complex terrain of "Ker Al Loch," which announces its shifts from poignant to intense with dramatic percussion and tempo changes. Here and throughout Kerber, the new and inviting layers Tiersen adds to his musical history of Ushant take listeners on a rewarding journey.