by Stephen Thomas Erlewine In the spring of 1996, the Doobie Brothers performed a benefit concert for the Wildlife Conservation Society, which was captured on the double-disc live album, Rockin' Down the Highway. During the show, all three of the group's lead vocalists -- Tom Johnston, Michael McDonald, and Patrick Simmons -- performed with the group, which was a first in the band's history. Fittingly, the Doobies used the concert to celebrate their past, playing hits like "Black Water," "China Grove," and "What a Fool Believes," but they also decided to showcase two new songs, which were never released on any previous album. Unsurprisingly, these songs pale in comparison to the hits, which the band play with affection, if not overwhelming energy. And since the group is laidback and nostalgic throughout Rocking' Down the Highway, the album is best-suited for fans who are also nostalgic for the band's glory days. In other words, it's pleasant, but entirely unnecessary.