score:1
My understanding is that you need to provide an itinerary for the duration of your stay in the Schengen Zone. If you declare that you are going to stay for the whole duration in Spain, and get the visa, this does not preclude you from travelling to other Schengen member states unless you get a limited territorial validity visa. That being said, you should not wilful mislead a Schengen member state during the application phase.