How do two examples differ in their approach to similar subject matter

What is included in the body of a business letter ?

This thinning would materially change the sound of the drum, evidence that although it might continue to be used for its original purpose of music-making or calling people to arms, it would now do so with a different voice. a musical instrument had become a trophy, and the new carvings were in fact branding, a statement of the north’s political dominance over central africa and of allegiance to islam.the drum had come to khartoum at a critical moment in sudanese history. in an audio version, stressing the word "branding" would do what for the listener? emphasize the word's importance and the idea that followsadd emphasis to the following sentencesignal that something important has just been repeatedadd emphasis to the preceding sentence

How whitman’s word choices and line arrangement in lines 4-8 create a feeling of vitality and motion in this section