Further updates: Pamplona at night is good. Lots of young folk with Basque haircuts tip generously. The city was gearing up for the running of the bulls, but there wasn't many buskers in the city besides a Polish dude named Lukas, a toothless German guy who sang classic rock covers, and a gypsy accordionist who took over the main plaza.
Tudela could be okay, but the desert region of Spain didn't seem as affluent as the tourist areas. The main plaza had a few cafes packed after siesta, but it was so loud that an acoustic act like us lost out. We ended up getting invaded by small children who tipped us 4 euros in tiny denominations.
Zaragoza is a joke. Busking requires "permiso" and permiso is hard to get. We had a police officer on us instantly while a gypsy lady down the street yelled at people to go to a restaurant. You're better off spanging or playing the cafes by the University, but I say just skip it.
Lleida is a college town with a shopping district just off of the train line. The shopping district has lots of external music to discourage street people. No competition, but not much money. After siesta, the shopping district closes. There's a college area, but those motherfuckers were stingy and hateful.
Tarragona is a decent place to make money. The Rambla (the main walking drag) was good but it is loud. Virtually no competition other than gypsies boiling in the sun. The old city was better than the Rambla, but dies down earlier (like 10). If you're going to make this city work, you have to play the cafes. We even got paid off never to return to one, which feels like victory. There's a bit of the Mediterranean feel without the Eurotrash element...
Vila Nova i la Geltru seemed like a good place to play, but the shopping areas are heavily policed. The African guys selling cheap sunglasses seem to have a look out posted, but if you don't, you'll find security guards, local and national police working in conjunction to boot your ass. We packed up when the Africans did, only to have the police stare at us. The plazas don't seem to be policed, so again: play the cafes.
Sitges: Decent, but Spain's arbitrary enforcement of rules was in effect. We played the day after the gay pride parade and made 22 euros for an hour only at night. The shopping street corner near the Farmacia and beach is a good spot, but make sure to move around. Also, this is a gay resort town, so people are in a decent mood. The police however shut us down after passing us multiple times throughout our stay in Sitges.
Barcelona. If you sleep in a park here, expect some Turkish dude to be staring at you while you snooze. Then he'll say, "no, its okay!" repeatedly and show up 2 hours later... Anyways, play the Market, not the Rambla. There are hustlers everywhere selling plastic castanets, squeaky noise makers (I got 2 of 'em for 1 euro), and self-climbing shit. They will ruthless jack your spot, so don't move. We made 48 euros in an hour and half by the Market, but when we got bold on the Rambla, the police came and they were NOT happy. They will take your shit if you fuck with them, but we played "stupid American" and they let us off.
Mataro was a joke. Somehow I got the sense that the locals were not up for street music. Lo and behold, five seconds into our first song, up rolls a cop, as if on cue... But there's lots of topless women on the beach, so I declare victory.
Blanes? Skip it. You could feasibly play it, but the type of tourism here is not receptive.
Girona: Decent place, but don't play in the old town. Only play the cafes that are hidden by the old architecture. We were tipped in weed, heroin (no thanks), and a chocolate waffle that tasted like a churro.
Figueres: The home of Salvador Dali and boy do they milk it! Didn't busk it because the streets were filled with city-financed music for San Joan Festival. Probably the best place to busk would be the Dali museum, but gypsy accordionist had it on lockdown.
CONCLUSION: If I had to do Spain all over again, I'd stay in San Sebastian and the other coastal areas like Bilbao. The Basque section was alot nicer than the Mediterranean by a long shot. The police tactic seems to enforce an unattainable "permiso" from the local council. The local council will not be nice to foreigners looking to make money off of tourists.
The reality is that Spain is really broke (30% unemployment) and tourism makes alot of money for Spain. Therefore, anything they construe as a threat to their livelihood is frowned up. Shopowners are usually baffled and the best tippers tended to be Dutch tourists. Young people between the ages of 18 and 35 seemed to be nonexistent.
Our Polish friend said that he had his guitar taken away 3 times in Spain (Grenada and so forth), so tread carefully.
GREETINGS FROM GERMANY (a MUCH better place for busking and cheaper beer!)
