Should I say 'in' or 'with,' 'an engaging' or 'a pleasant' in the sentences below?

Should I say 'in' or 'with,' 'an engaging' or 'a pleasant' in the sentences below?

1. (In, with) vibrant/resonant voices, the children sang the national anthem of their country.

2. In (an engaging, a pleasant) voice, Miss Scott asked the children to join her in singing and acting out the children's song she had composed herself.