Final answer:
Joe Turner was described as a "blues shouter" because of his strong, powerful voice that allowed him to be heard over the loud music and crowds, characteristic of the singing style required in the era before the widespread use of microphones.
Step-by-step explanation:
Joe Turner, a jump blues singer, was often described as a "blues shouter" because of his powerful vocal style that could be heard over the noisy crowds and the loud music without the need for amplification.
This term originated in the blues music era, which evolved from African-American spirituals and gained popularity during events like the Harlem Renaissance.
Blues shouters like Turner needed to project their voices powerfully to be heard, which stemmed from the tradition of forceful singing styles like those found in lined-out hymns and call-and-response patterns.
The ability to 'shout' the blues was a hallmark of artists like Turner who commanded the stage with their vocal prowess, in an era when microphone technology was either limited or non-existent.