AKA a steel drum, a steel pan consists of the top cut off a 55 gallon drum and the top of that hammered into a concave shape with big dimples in it. When polished up nicely, each of the dimples will produce a different musical note when struck with a wooden mallet. The pitch range is affected by how much of the drum you leave attached to the concave part. Steel pans are percussion instruments and sound damned cool. In drumspeak, the individual sound produced by a pan is "pwow", among others.