A ladainha is a solo narrative sung by one person — traditionally a mestre — to open the Roda. It's often a story, a piece of history, a bit of philosophy, or a warning, and everyone else stays quiet and listens until it's finished.
Once the ladainha ends, the song transitions into a corrido: a call-and-response song sung by everyone. The leader sings a line, and the whole Roda answers back together, usually repeating a short, memorable phrase. This is where the group actually gets involved vocally, and where the game itself typically begins.
The ladainha sets the tone and context; the corrido sustains the energy for however long the game runs. Not every Roda includes a full ladainha — many jump straight into corridos, especially in faster-paced or more informal settings — but understanding the structure helps you recognize what's happening and why, instead of just waiting for singing to start.