DENVER (CBS4) – A United Airlines flight attendant joined passengers in grabbing a ukulele and mandolin to sing Christmas carols during a delay on the runway at Denver International Airport. The passengers were waiting to take off on Thursday after a small accumulation of snow.

The flight attendant joined some passengers who picked up a mandolin and ukulele and proceeded to serenade the waiting plane with a little holiday cheer.

Denver’s official snowfall as measured at DIA was 0.5″ as of 11 a.m. Thursday.

Airport crews were brushing away mostly light snow with snowplows on the runways.

FAA has lifted the traffic management plan for DEN and snow is tapering off with flurries possible the rest of the day. Lingering delays are possible so please check your flight status. — Denver Int'l Airport (@DENAirport) December 21, 2017

Some delays for travelers were reported as being almost an hour long, but most flights were arriving and departing on time.

Snow teams getting their first taste of winter this year. All 6 runways are open thanks to these dedicated men and women. #cowx pic.twitter.com/fhPQpPJC5G — Denver Int'l Airport (@DENAirport) December 21, 2017

The airport is starting to feel the increase in activity as holiday travelers start to pour in and out.

Nearly 2.5 million passengers will pass through the airport from now until the new year.

Friday is expected to be the busiest day during this holiday period.

DIA officials say they are staffing up security checkpoints to help manage the lines and to make travelers’ trip through security as smooth as possible.