An icon of music history is announced at the Avo Sessions Basel. A small choir and three musicians were Mavis Staples on the side, but the bubbly 73-year-old presented with her powerful voice all in shadow. Their music contrasted with Nick Lowe's often melancholy songs-"cheerful gospel," which came from the heart. Since this kind of music can never have enough votes, Mr. Lowe came for two songs back on stage to support Mavis and his band. The music was accompanied by atmospheric, subtle and colorful lighting.