The dispersion of aerosols was studied experimentally in several concert halls to evaluate their airborne route and thus the risk of SARS-CoV-2 spreading . For this, a dummy is used that emits simulated human breath containing aerosols with a mean diameter of 0.3 µm, and horizontal exhalation velocity of v =2.4 m/s measured 10 cm in front of the mouth as well as CO2 . Aerosol and CO2 concentration profiles were mapped using sensors placed around the dummy . No substantial enrichment of aerosols and CO2 was found at adjacent seats, provided that: (1) there are floor displacement outlets under each seat enabling a minimum local fresh air vertical flow of vv =0.05 m/s, (2) the air exchange rate (ACH) constitutes more than 3 h-1, and (3) the dummy wears a surgical face mask . Knowledge of dispersion of viral droplets by airborne routes in real environment helps to establish risk assessment when re-opening concert halls and theaters after pandemic lock down.