The band is playing louder and happier because it is the start of the Season.

Miss Brill is a lady that enjoys sitting in the park and people watching.  She enjoys listening to the band that plays every Sunday.

There were a number of people out this afternoon, far more than last Sunday.  And the band sounded louder and gayer. That was because the Season had begun.

The band makes Miss Brill feel like a part of the action in the park.  She tells herself that she likes to sit alone on the bench every Sunday because she is a people-watcher and enjoys commenting on the park’s patrons.  However, her attempts to hide her loneliness from herself fail when the couple on the special bench mock her.

When Miss Brill describes the people, she is really describing herself—she just won’t admit it.

Other people sat on the benches and green chairs, but they were nearly always the same, Sunday after Sunday, and—Miss Brill had often noticed—there was something funny about nearly all of them.

Miss Brill does not appreciate her real role in the park.  Although she is a fixture there, she is not understood.  She likes to think of it as a diversion, but it is really just a futile attempt to be relevant.  When she hears what others are saying about her, she laughs it off at first.  Her attempts to delude and protect herself from the sad reality of her life finally come crashing down on her.  When she hears crying, she knows that it is really herself.