"The Thunderer" is a march composed by John Philip Sousa in 1889. The origin of the name is not officially known, though it is speculated that it gets its name from the "pyrotechnic [effects] of the drum and bugle in [the] score." It is also one of Sousa's most famous and is one of the more difficult compositions to perform.
The piece is in much the same manner as most of Sousa's music; however, it is one of his first "distinctly American-sounding marches." The march follows the standard form (IAABBCDCDC) that is used in many of his other works. As is common, his themes are contrasting. During the repeat of the B section, Sousa introduces new countermelodic ideas. The trio is songlike. There is a ritardando leading into the repeat of the final theme, segueing to the piece's conclusion.