This refers to the seventh inning of a baseball game, which is often associated with a break or a chance for the team and fans to relax and recharge. It's a significant moment in a game known for superstitions and rituals that can impact the outcome.
Many fans have a tradition of singing at the stadium during the lucky seventh inning.
seventh-inning stretch
This phrase also refers to the traditional break that happens between the seventh and eighth innings in a baseball game, where spectators often stand up, stretch, and sing, contributing to the overall atmosphere of the game.