With an **invitation** of course!
1) Make sure you're on the **group page** that you want to invite people to.
2) On the right side of the screen, under **"Members,"** click on **"Invite User."**
3) Enter the person's **email address** (separate multiple email address with a comma).
4) Set their role, a **viewer** can only see tracks, a **member** can edit and add tracks, and a **moderator** has all the same power that you, the group owner has.
5) Add a **personal message** so the person knows why they're being invited to your group.
6) **Send** the invitation!
7) When they respond, they're in, **that's it!**