CALGARY—A bird’s-eye view of a popular live music venue on its first night at the Calgary Stampede showed hundreds of people standing close together, waiting for a swab or to hand over proof of a COVID-19 vaccination. By night’s end Thursday, thousands had come in and out of the 18-plus party tent called Nashville North, believed to be the first major venue in Canada to enforce testing or require health care information to enter. The popular open-air concert hall is open each day and night during the 10-day western festival and rodeo. New safety measures adopted by the Stampede this year include cutting daily attendance in half. Staff and volunteers are also required to wear masks and get COVID-19 rapid tests. In order to enter Nashville North, patrons must have proof of having had at least one COVID-19 vaccine shot two weeks prior. Otherwise, a negative rapid test result at …