Constructive interference in performance halls and the elimination of echoes are reasons why choir concerts better in performance halls than in gymnasiums.
Constructive interference is a phenomenon which occurs when two waves travelling in same direction and which are in phase add up together to produce a wave of greater amplitude.
Constructive interference occurs in performance halls while destructive interference occurs in gymnasiums.
Also in performance halls, echoes are minimized due to the padded walls and the curtains while echoes which disturb choir concerts occur in gymnasiums.
Therefore, choir concerts better in performance halls than in gymnasiums because of constructive interference in performance halls and the elimination of echoes.
Learn more about constructive interference and echoes at: https://brainly.in/question/2378717