How and when is 做 used as the verb "to be"? Can someone please clarify how and when 做 is used to mean "to be" e.g.


  不愿做奴隶人们


I am familiar with 做 meaning "to do" or "to make", and I would expect that if I was saying "I am a slave", “我是一个奴隶“ would be preferable to “我做一个奴隶“

Why is 做 used in the first instance?
"做" has a meaning of "充当，担任" (serves as, work as) (from 现代汉语词典 Modern Chinese Dictionary). It is different from "是" (to be).

The nuance of English and Chinese here is a little different. In Chinese, we don't say "I don't want to be [a slave]" (我不愿是[奴隶]). It is always "I don't want to serve as (become, etc.) a slave" (我不愿做(成为)奴隶).