These pictures may give the impression that the square is lightly peopled, but not so! It is usually packed from side to side.
I am pretty sure the area is not square, but it may be an optical illusion. I think the sides spread out. At one end is a range of video screens which vary between leaping flames and blue waterfalls:
On both sides of the square are eating areas with orchestras playing in turn.
The group playing is at extreme right, under the canopy. St Mark's church is at the back, and the people in front are in a long line waiting to get in. There is another long line waiting to get into the tower.
This band is around the corner, in the entryway to the square. The sea is to our left.
This group of performers appeared, played, and enjoyed having their pictures taken many times.
And on another occasion this choir turned up, began singing, and soon had a big crowd listening. I don't know who put the hat there, but it was collecting money.