To answer "Can you ignore 'spam' music?": Yes, most of the time. In public places, it would have to be exceptionally loud before it bothered me.

As for concentration, I do have problems with music affecting my concentration when reading, writing, trying to do numbers, etc. I find this more of a problem if the music is something I want to listen to, e.g. folk, where I find I only really concentrate on one task or other - usually I switch the music off in these situations.

As for shopping, perhaps my attitude to shopping helps. I loath it and just view it as a task to get over and done with. It doesn't demand any thought other than how to get it over and done with in the shortest possible time.

Jon