On Saturday, shortly after Iran formally swore in new president Hassan Rouhani, many Iranians in and outside the country were celebrating the departure of his predecessor, Mahmoud Ahmadinejad. Whether in private gatherings, public celebrations or just on social media, they're often doing it with a musical little phrase: "Ahmadi bye-bye."

The chant, always in English, actually goes back to the 2009 "green movement" protests when mass demonstrations challenged Ahmadinejad's disputed reelection victory. The phrase, part sung and part shouted in street protests, was as much an aspiration as a demand that Ahmadinejad yield to public pressure and step down, allowing challenger Mir Hossein Mousavi to take the presidency. While there are important differences between Rouhani and Mousavi, both are considered potential reformers and are popular among Iranian youth and liberals. For many, this weekend allowed for a moment of vindication after the pain and humiliation of 2009.

Here's a brief clip of Maz Jobrani, a Tehran-born Iranian American comedian, explaining the chant and how it's performed:

An Iranian student told Radio Free Europe's Golnaz Esfandiari that he would be celebrating Ahmadinejad's departure with friends over the weekend. "He brought us only shame and problems," he said. "Tonight and tomorrow, I will sing, 'Ahmadi, bye-bye.'"