**You cannot hear or see the internal performances of the Bird's Nest Concert without purchasing tickets**. Due to reflection, interference and other phenomena during the transmission of music, as well as the obstruction of the Bird's Nest building itself, the volume of the music is already very low when it is transmitted to the outside, making it impossible to hear the effect of a concert. At the same time, in order to avoid disturbing surrounding residents, the sound at the concert will also be adjusted, and the auditory effect outside the Bird's Nest will be even more limited. Therefore, it is recommended that friends who want to enjoy the Bird's Nest concert purchase tickets so that they can truly feel the atmosphere and performance of the concert.