The third album from Etran Finatawa, the band comprised of a mix of the Wodaabe and Touareg people, captures the development of an already well-formed sound. It's based in the desert blues style, not a million miles from Tinariwen and other similar performers, but the group adds its own touch. It's more rooted, more hypnotic -- witness a track like "Daandé," where the groove simply mesmerizes. Recorded in the middle of a European tour in 2009, the foremost elements are percussion and polyphonic singing. These buoy everything up, with the guitar, also a powerful element, much in the background. The lyrics are unabashedly political (although not in English), with "Diam Walla" reflecting on the problem of water for the desert people, and "Aitma" an appeal to the people of the world to find common ground rather than fighting each other. The differences between this and their previous releases are subtle, but Etran Finatawa are progressing, defining a particular sound that makes them stand out. It's an album that needs, and deserves, a lot of plays to impart its secrets, but the time spent on that is an investment, not wasted.