"VII. Neptune, the Mystic" includes two women's choruses, each containing two soprano sections and one alto section.
In terms of musical composition, different vocal ranges are, essentially, different instruments, as they have to be written for separately by the composer, and they are each specifically specified in the score.
In terms of musical composition, different vocal ranges are, essentially, different instruments, as they have to be written for separately by the composer, and they are each specifically specified in the score.
I hope that that clears things up.