The side-effect of Rod Stewart's superstardom has been that few take him seriously as an artist. Rhino's four-disc box, The Rod Stewart Sessions, is designed to prompt re-evaluation, showcasing an artist at work: an artist writing lyrics, stretching out melodies, changing arrangements, anything he can do to get a piece of music to work. This, naturally, is not passive listening; although the differences are often notable, especially on the earliest tracks, it demands attention because so many of these are working tracks, not finished masters. As the set winds to a conclusion in the late '90s — the last album covered is Rod's Brit-pop homage When We Were the New Boys, tellingly also the last rock & roll album he's made as of this 2009 release — outtakes begin to outnumber the rough cuts, and there are some good ones, including takes on Paul Weller's "Changingman" and Oasis' "Rocking Chair." Still, it takes a little bit of effort to get there, as the set dips in interest during the mid-'80s, when Rod hit a creative lull, but that is easily overshadowed, as it always is, by the glory of his '70s work. Here, there's an undeniable charge in hearing Rod muck about in the studio, figuring out the words for "Maggie May" and "You Wear It Well," figuring out how to give "Los Paraguayos" a kick, joking around on the music hall romp "My Dad's Trouser." True, this is all the province of the dedicated, but for those curious listeners who decide to wade into these deep waters, they will indeed find a sharp, engaged, interpretive singer and songwriter, the artist who has been obscured in the wake of Rod's superstardom.