The act of bringing things or people together is often referred to as "unification" or "integration." In various contexts, it can also be described as "assembly," "gathering," or "collaboration," depending on the nature of what is being brought together. These terms emphasize the process of forming connections and creating a cohesive whole.
a leader
Assembly would be a name for putting things together.
two people singing together is a duet
Some people can say things over the phone that they cant bring themselves to say in person...like..I love you or lets go out together again tomorrow...or lets go steady...things like that...other people just like to talk a lot and feel like they have company while on the phone.
guillotine
no
Quartet
A duet.
Choir
Well, different people call them different things. Some people call them Aqua Jumps, and some people call them Blobs!
Scribe
gatherings or gathering