An unironic sweetness is at the heart of most Christmas music — just think of "Joy to the World" and "Deck the Halls." Even the more sober tunes, like "Silent Night" or "Little Drummer Boy," are catchy, straightforward, and wholly well-intentioned. These are praise songs, after all. For those willing to embrace such earnest holiday cheer, Berkeley guitarist Sean Smith presents Christmas, an acoustic, instrumental album of no-frills covers and a couple of equally unpretentious originals. His playing seems almost willfully naive: lots of single-note melodies, simple harmonies, no-fluff arrangements. The recording pleasantly surprises; the live show will, too.