A Rubens' tube is a pipe full of flammable gas with a row of holes along the top; sound played into one end makes the flames rise and fall along its length as the pressure varies. This 2014 Veritasium video shows a two-dimensional version, the Pyro Board, built by Sune Nielsen of Fysikshow Aarhus in Denmark, with flames across a whole plate rather than a line.
Derek Muller's explanation is the useful part. The pressure variations of the standing wave change the gas flow rate through each hole, which changes the flame height and colour, so the pattern you see is a map of pressure across the box. It is the same nodes-and-antinodes picture as a Chladni plate, drawn with a different medium.
At the time of writing it has been watched more than 16 million times. It is also a reminder that this is not a home build; a box of propane and open flame needs the kind of care a physics show team brings.