Where will Foo Fighters perform in Barcelona? Note: only 130 invitations avalaible

Foo Fighters, one of the biggest rock groups in the world, have chosen Barcelona to perform a 'secret show' on Saturday, September 16, a day after the publish of their new work 'Concrete and Gold'. Let's remember that they were the headliners of Mad Cool festival in Madrid last summer.
The concert can only be accessed through invitations that various media, the M80 radio and the newspaper 'El País', distribute in competitions.
The first question to know is: Foo Fighters are going to make a long show or just a few songs and photos with the contest winners be viralized instantly?
What we know is that the M80 have 40 double invitations, 80 people. The newspaper 'El País' have 25 double tickets. You can only opt for 130 invitations in total. If we consider that there would be other 100 or 200 invitations to distribute between Sony and the press, the fact is that a small room is suitable for this event and the options are endless in Barcelona.
Given the small number of invitations we could overlook that the three concert halls of Razzmatazz in Barcelona are not scheduled at the concert schedule next Saturday. A pretty strange fact. Speculating without any shame would say that, by capacity, the ideal venue would be the Razzmatazz 3 but by relevance of the group should be the first, even if it was half empty.
But the fact is that we have no idea where they are going to act and, given the small number of invitations, it does not seem that the group is going to make a long and brilliant concert.
How to get one of these invitations?
The M80 radio station has launched a contest that ask to upload a video or photo on Twitter or Instagram "showing why they are the biggest fans of Foo Fighters" labeled #M80oroFF. A jury of the radio will choose the most original ones.
In 'El País' it's easier-but there are less options-: over 18, register on a website and a free text of less than 500 characters, explaining "What Foo Fighters song does not have to be missing in the set list of its Barcelona's concert and why? ". Good Luck.