The last time we heard from pairing of Belgian band YellowStraps and producer Le Motel, the low-key enchantment of “Pollen” was the product. On “Valium,” the combination proves a winning one once again. Mingling the smoky, jazzy mood that gave “Pollen” and follow up “Flamingo” their mellow magic with more overt nods to hip-hop (incorporating the criminally underused 808 cowbell was a fine choice), “Valium” manages to subtly push forward the formula quickly being carved by YellowStraps’ growing catalog. The accompanying video is equally charming, a pretty, sun-bathed journey through the woods to a secret house where band and producer travel to make music. It’s a simple concept executed with a sense of fun and wonder, a further reminder that effective beauty doesn’t take big budets.