Conversation so far:
Why did Gavin leave Titãs?
Gavin stated that he was physically and mentally exhausted because of the Titas tours and album releases.
Did Titãs replace Gavin with anyone?
Yes, Drummer Mario Fabre, who has remained with the Titas since then as a session member.
What tour did Mario Fabre go on with Titas?
Mario Fabre went on the Sacos Plásticos tour with Titas.

Question: What happened for the 30th birthday?
Self-contained rewrite: What happened for the 30th birthday of Titãs?