Beginning in which century did musicians begin to indicate the degrees of loudness or softness in their music?

Which of these was important in spreading Martin Luther's religious ideas?

a. Morley's Triumphes of Oriana b. the telescope c. Shakespeare's Hamlet d. the printing press

Hard bop bands kept the mainstream jazz audience engaged by emphasizing

a. a strong backbeat b. comic stage routines c. at least one vocal on most hard bop LPs