Learning a vocal part often means needing access to an instrument and having the skills to play it. What is more, knowing a part does not always translate into being able to sing it with a group as that part gets lost in the other vocals and drowns in a sea of sound.
All that changes with Sing In Parts.
Listen to one vocal type and practice
Increase or decrease the volume of other voices to practice singing your part while hearing the other parts. No need to coordinate practicing with others.
We do not all have access to a piano or have the ability to play it. Learn while making dinner, in the dorm room, or on the go.