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Concierto sorpresa de Skalariak en la calle Descalzos
But the quality is usually good: txalaparta, groups from East Europe, African music, groups from the Andes, new and old rock players, etc. Sometimes they also dance. It's not something you will find in the programme. It just depends on when and where you are.
Of course, there are also admission concerts at night and open-air dances for free. You can have a look at the official programme. In the mornings there are also singing concerts on offer.