One other thing about that concert

Mercedes Sosa is a very big name in her genre, which is Latin American folk music.

A lot of Latin American folk music is political, given the upheaval many of the countries in this region have experienced in the recent past. In addition to love songs and hymns to natural beauty, there is a whole class of musicians whose work is known as "Nueva Canción" (literally, "New Song"). Their music directly or indirectly deals with freedom, poverty and other political issues.

The Wiki article about Mercedes Sosa says, in part:

A supporter of Perón in her youth, she has favored leftist causes throughout her life. After the military junta of Jorge Videla came to power in 1976, the atmosphere in Argentina grew increasingly oppressive. At a concert in La Plata in 1979, Sosa was searched and arrested on stage, and the attending crowd was arrested. Banned in her own country, she moved to Paris and then to Madrid.

Still, that was long ago and far away - in several senses. The fans of Mercedes Sosa, Silvio Rodríguez and other members of the Nueva Canción movement tend to be politically aware grownups who love good music and also support the message behind it. They are well educated and, all in all, good folks to have a drink with. Not a rowdy bunch.

And the venue is small - it's an indoor sporting arena built around a basketball court, with a single-tier balcony all the way around. Its total capacity is 20,000, but when there are concerts, the stage takes up about a third of the floorspace and they cordon off about 25% of the balcony area, since it ends up behind the performer. Folding chairs are set out on the floor area not taken up by the stage, but really it's not worth paying extra to sit there, as the balcony has 16 steeply angled rows of bench seating - it's not that comfortable, but the view is good from anywhere.

Oh, right. I was saying. The venue is small (for such a big name - I also saw Sting there, years ago), and the crowd isn't likely to get too crazy. I wasn't surprised to see a few police officers standing around outside when we got there - you expect to see some at any public event. But, all in all, it seemed like there were more than might be called for at a grownup concert of music that is powerful and moving, but, musically, really quite calm.

Anyway, there was a warmup singer on when we got there. We found a spot halfway up the balcony, just even with the front edge of the stage. We were maybe 50 feet from center stage - I'm basing that on the width of a basketball court and where we were relative to it.

The place filled up while the warmup singer was on and then, during his last song, a dozen people or so filed in from a different entrance and took their seats in the front row of the folding chairs. The crowd started making so much noise, I finally asked Alex what was going on.

Turns out, that was the president of Costa Rica, seated front & center. (I hadn't paid attention to them as they came in, but once pointed out, I did recognize him.) Now I may have thought there were a few more police officers than necessary for a Mercedes Sosa concert, but there sure weren't that many. Maybe a dozen or so. No particular additional security was visible - none of the police officers came inside.

The crowd did a little spontaneous political shouting (anti CAFTA, which Arias is for), but were well behaved once the music started.