It was at Confitería Ideal, on Suipacha, which Lonely Planet says is one of the tango meccas of BA. It happens to be about 10 minutes' walk from my hostel so I went round. You don't have to book, and it only costs AR$60 for a 90-minute lesson. Seriously can't complain!
The building was absolutely gorgeous. And the hall we had the lesson in was incredibly grand, with red, black and gold pillars, tables and ornaments. The pillars culminated in an impressive roof with a patterned atrium. You could almost smell the tango.
In the lesson we went through the basics and learned a basic routine. We also learned to "show intention through your chest". My chest has never had such intent, I can tell you now.
The teacher was great. She was passionate and intense, and only spoke Spanish, so when I danced with her she stared into my eyes and occasionally uttered commands and a few gratifying 'Muy bien's. There was an official translator too, so although I understood quite a bit of what she was saying, and picked up some new dance-related vocabulary, it was helpful to have him there.
I left feeling oddly confident, and I thoroughly enjoyed it. So did Nik, a guy I met in Iguazú, as he was keen to do a class too. Now I can appreciate the tango I see around the city a bit more. And seriously, the tango is everywhere. I was worried that I might miss out so I booked tickets to see a professional performance at Café Tortoni. And then stumbled across dancing at the park, outside a restaurant, in a souvenir shop... But I'm still glad I got to do the whole red curtain and stage thing at the Café. Definitely go to La Boca and see tango at Caminito. The atmosphere's fantastic. But go during the day, and give yourself time to leave La Boca before dusk.
So to sum up, if you're in Buenos Aires and looking for a good, and cheap, tango lesson, Confitería Ideal is... ideal.
I've got one day left in this lovely city, and then I fly to Peru. Milena left last night to explore other parts of Argentina. But we'll meet again in Cusco for my 25th birthday, so I'm looking forward to that. I'm really enjoying Argentina. It's a really funky, cool country. I might try to hop across the Andes (casual) from Santiago and visit Mendoza if I have time at the end of my South American travels...