In the 19^th century, a new type of instrumental ensemble emerged. It expanded the woodwind, brass, and percussion sections of the orchestra and did away with the string section. This new ensemble, known as a band, became hugely popular during the 20^th century as military, school, and community bands sprung up all over the United States.
 

The orchestra was the primary instrumental ensemble for centuries, so when wind bands first began to form, they had to play arrangements (adaptations) of orchestral music. That soon changed, however, as composers like Gustav Holst, Percy Grainger, James Swearington, and Ralph Vaughan Williams began to write music specifically for bands. Today there are many composers who write music specifically for winds.

Band instrumentation is not as standardized as that of orchestras. Bands can vary widely in size and instrumentation. There are even bands called wind ensembles that have a rotating roster of players, and the size of the band fluctuates depending on the needs of the music that they play.
 

Marching bands played a significant role in the promotion of band music during the 20^th century. A marching band differs from a concert band in that the concert band performs seated while the marching band moves. Marching bands were initially formed to perform in parades, but now many marching bands perform elaborate choreographed movement. Most high schools and many colleges have field bands that perform at football games during halftime. Drum and bugle corps perform a similar style of choreographed marching that is independent from football. Composers like John Philips Sousa wrote a wide repertoire of marches, which today are played by marching and concert bands alike.

A concert band is typically led by a conductor. It is the job of the conductor to interpret the composer’s intent for the music. (S)he achieves this by reading the printed music (called the score), and by researching the song’s history. The conductor guides the band in their preparation of the music so that they can deliver the best possible performance.
 

There are also leaders within each section of the band called principals. Band musicians are seated in order according to their skill, with principals holding the first chair position. Marching bands have additional leadership positions, the most significant being that of the drum major. Contrary to what the name suggests, a drum major does not necessarily play the drums. (S)he marches in front of the band in parades, calls out commands to guide the band’s movement, and conducts the music.