As they boarded a connecting US Airways flight from Charlotte, North Carolina, to Fayetteville, Arkansas, the crew told them they would have to check their violins.
"We were stopped as we entered the plane by the captain and his stewards. They told us that no musical instruments were allowed on the plane," Kendall wrote in a statement provided to TODAY.
"We told them that as a touring act, we have flown on countless US Air flights……with absolutely no issue."
More from TODAY
Summer gear it's worth cheaping out on
Magical! Get a sneak peek of the new Harry Potter ride
Real or replica? Tourists line up to see fakes
Kendall said the captain then asked both men to get off the plane, so they complied and waited on the tarmac until a complaint resolution official could weigh in on the issue.
That's when De Pue did what any frustrated musician would do: He took out his violin and started playing right there on the tarmac, accompanied by the roar of plane engines nearby. Kendall began recording the unusual concert on his cell phone and uploaded the video to YouTube. (Warning: Video contains expletive.)
Read MoreExposing hidden fees: Feds seek more protections for air travelers
"How many artists have to deal with this [expletive]?" Kendall says in the video. "This is unbelievable."
"Bach would be very upset," adds De Pue. "Unreal, guys. We've got to fight this… this is wrong."
The pilot appears to ignore them as they wait.
The men point out the FAA Modernization and Reform Act of 2012 allows airline passengers to carry a violin, guitar, or other small musical instruments on board a plane if they can be "stowed safely in a suitable baggage compartment or under a passenger seat" just like any standard carry-on baggage, as long as there is such space available when the passenger boards the aircraft.
Read MoreWhat's next for airline fees? More ways to pay
It's not clear whether there was any space left on the 70-seat plane, and the airline is looking into what happened, said US Airways spokesman Bill McGlashen.
"We do apologize to these musicians for yesterday's delay in getting to Fayetteville," McGlashen said. "Sometimes, there's a judgment call on some of the smaller regional jets and we did offer a plane-side check, so we do recognize that musical instruments are fragile."
The captain has the final say on such matters, he added.
De Pue and Kendall were ultimately told to either put their violins in the plane's cargo hold or forfeit the flight. Worried about their valuable instruments, they decided on the latter and were rebooked on a later flight. This time, they were allowed to fly with their violins in the cabin.
"We recognize their frustration," McGlashen said. "We wish them good luck and good playing at the Arts and Nature Festival."
—By A. Pawlowski of TODAY