Few musical marriages have been so magical, so intuitively right, as that of the great blues singer Howlin’ Wolf and his guitarist, Hubert Sumlin. From the time he joined the blues legend’s band in 1954 until Wolf’s death in 1976, Sumlin played a central role in crafting some of the century’s most memorable and influential American roots music. His economical, stinging fills, unusual rhythmic approach and perfectly placed bent notes are as integral as Wolf’s growl to the blues power of classics like “Spoonful,” “Smokestack Lightnin’,” “Killing Floor” and “The Red Rooster.”