What could cause pain in right trap and shoulder/clavicle clicking?

Any # of things: Differential would include painful/arthritic AC joint (joint at end of clavicle), rotator cuff tear or intractable tendinitis, labral tearing (cartilage surrounding socket which helps stabilize joint), altered mechanics or abnormal motion of the scapula (shoulder blade) on chest wall. Bottom line if chronic and interfering with daily activities/work should be evaluated by orthopedic surgeon.