The Atlanta Symphony Orchestra's October calendar lists The President's Own United States Marine Band on Monday, October 26, at 7:30 p.m., as a free event. That is a worthwhile early-week option if the weekend gets crowded and you still want a substantial live performance.
The Marine Band is a full professional military ensemble with a long history of concert performance. The attraction here is the quality of the music and the chance to hear it in Symphony Hall without a normal symphony ticket price. Free events can still have reservation or capacity rules, so check the orchestra's listing before heading downtown.
If the time works, treat it as a simple Monday-night cultural outing. It offers a fresh musical choice without the commitment of an expensive concert or a late show.