You’ll never accuse Issa Bagayogo of pandering to an audience with his singing.  His baritone vocals tend toward the monotonous and mechanical, and when he goes into one of his all-too-frequent “talking blues” riffs, you might as well be listening to a Malian computer programmer spitting out code.  That’s why the techno underpinnings to the songs on Tassoumakan (Six Degrees) work so successfully.  Samples, drum machine loops and mix effects join hands with acoustic instruments, such as balafon and Issa’s kamele n’goni lute, plus Mama Sissoko’s eminently welcome electric guitar.  Female vocalists, including Awa Diabate and Yalomba Traore, add a much-needed sweet lilt to performances that favor dark mutterings over melody or emotion.  The cool electronic arrangements in the service of appealing grooves help put the songs across.  “Kanou” has unexpected piano accompaniment and a West African trip-hop feel, while “N’Deri” broadens the sonic palette to include a cello.  The only thing missing from this addictive clutch of nicely arranged songs is a strong lead vocalist, and Issa does come maddeningly close at times.  Maybe he’ll take the plunge and try expanding his emotional outreach next time around.