I was in the crowd of a heavy metal concert and got crushed between people and a metal barrier, back and ribs are very sore, should i get it seen?

Yes: Crushing injuries can cause some rib sprains and even fractures. Depending on the force applied to your back it is even possible to have a fracture there. I would advise having your MD perform a full exam on these areas to help determine if it's just bruised muscles or something else. If you start having rapid and significant breathing problems before your appointment consider an ER evaluation.