ATLANTA—Robin Hancock gently played her steel tongue drum with a pair of mallets, producing a set of soothing, mystical tones. They blended with the soft sound of chirping birds and bubbling creeks pouring from a Bluetooth speaker. Her warm voice invited the two visitors in the dimly lit room to slip into a nature setting of their choosing. The 20-minute guided meditation took place at an unlikely location: Atlanta’s Hartsfield-Jackson International Airport, which until 2020 was the world’s busiest passenger hub. The airport interfaith chapel’s executive director, Blair Walker, introduced the meditation sessions last fall in the midst of the COVID-19 pandemic. People were noticeably more stressed during the past year, Walker said as he stepped out of his office onto the second-floor gallery, which overlooks the airport’s main atrium. Walker is an ordained minister who previously worked in higher education and public health. He said people have been quicker …