Two groups of desert nomads meld their music in the sparse, spellbinding songs of Etran Finatawa, a band from Niger. Etran Finatawa, which means “stars of tradition,” played its mesmerizing U.S. debut at Symphony Space in a World Music Institute concert. It was easy to tell who was who. Three Wodaabe musicians wore long, almost rectangular robes, hats with a single feather pointing skyward and white stripes of face paint down their foreheads and noses. Three Tuareg musicians wore ornately embroidered burnooses and robes. For centuries, Tuareg and Wodaabe nomads have traversed the Sahel grasslands and Sahara in northern Africa, herding cows, camels and goats, and sometimes feuding over water and pastures. They now face the erosion of their age-old cultures and the desertification of their lands. Etran Finatawa responds in its songs while it symbolically reconciles the two groups. “A man is nothing when he is alone/People need other people,” they sang in “Jama'aare,” from their second album, “Desert Crossroads” (Riverboat/World Music Network). Many of Etran Finatawa's lyrics insist on the value of heritage. Meanwhile, the music looks forward, altering that heritage by bringing together Wodaabe and Tuareg musicians and by using instruments that were introduced to Tuareg music in the 1970s: electric guitar and bass. From stoner rock in California to African nomad songs, the desert fosters drones. Most of Etran Finatawa's songs revolve around one of Alhousseini Mohamed Anivolla's repeating guitar lines: not chords, but picked, syncopated notes and trills. While the guitar lines probably derive from regional fiddle music, Americans might also hear a kinship with the oldest Delta blues. The other instruments are portable and unplugged: calabashes, clapping hands and the jingling, metallic percussion that Bammo Angonla, a Wodaabe, held in his hands and had strapped to his leg. Their instruments use the environment. A Tuareg drum is stabilized by sand; the Wodaabe float a calabash in a larger calabash basin of water, for a steady, deep-toned pulse. The songs ride multilayered six-beat and four-beat rhythms that seemed easy and natural until clapping audience members tried, and failed, to keep up. While the rhythm section was merged, the vocal styles were distinct. The Tuaregs sang in open, equable voices while the Wodaabes sang in high, pinched tones that must carry a long way across sand and savanna. __