What is the big band era?
What starts small can become big, as did the Big-Band era. In the later 1800's, "Negro" slaves were given European band instruments in order to domesticate them away from mere "savage" drums in their musical expression; Clarinets, Saxophones, Trumpets, Trombones, Western drums and cymbals, etc. Banjos were added as well. The problem - little to no music instruction. The slaves communicated in the fields and in their communities with the voice, so they merely began imitating their vocal stylings when they blew their instruments. This African-American style of vocal imitation and freely improvised musical exression over basic chordal harmony became the "Dixieland Jazz" music of the early 1900's; the first inginous art form of and from America. This has proved to be one the greatest musical/social gifts the entire world has ever known. "Dixieland" became so popular that similar small bands popped up all around the country, especially in the more metropolitan areas. Blues and ragtime, along with a rich local brass band tradition and many other influences, specifically came together in the late teens to early 1920's in New Orleans, Louisiana to create this new type of music, "Dixieland Jazz." Dixieland is also known as "Traditional" jazz or "New Orleans" jazz. As jazz gained in popularity, it spread north from New Orleans to Chicago, New York, Kansas City, and across the Midwest to California. In some contexts, size does matter, and some bands began adding more members to their sections. The musical people who wrote music for these growing ensembles (arrangers) competed for audience attention. Into the late 1930's and then the 1940's, the bands grew into the standard Big-Band (Dance Band) size - 5 Saxophones (with occasional Clarinets), 4 Trumpets, 4 Trombones, and a Rhythm Section (Piano, Bass, Drum Set, and sometimes Guitar). The music performed by Big Bands was called "Swing," a type of music that people could dance to easily. It was performed in a triplet swing rhythm style. This energetic dance music was wildly popular for almost two decades, with the Swing Era extending through the mid-1940s. During this time, thousands of Big Bands played across the United States. This became known as the - "Big Band Era," and continued into the 1950's, 60's, 70's, and is still alive to this day. Jr. High and Senior High schools across America and the world still teach students in the Big Band Jazz ensemble tradition. Much Swing music echoes the "call and response" pattern of early spirituals, where different sections of a choir would sing various parts of a piece, handing off the melody from one to another and varying it with each transition. In a Big Band, the melody would be played by one section (e.g. brass) and then echoed by another, such as the reeds. The whole group would also play as an ensemble, again replicating those parts of a spiritual where the choir sang as a unit. A good example of this style is Benny Goodman's performance of Don't Be That Way, arranged by Fletcher Henderson.
Songs tended to be no more than 3 minutes long because there weren't yet LP's or CD's, only singles. Most followed an "A-A-B-A" pattern: the basic melody was performed once by the band, then again either by the band or by a vocalist; then a variation on the melody, and finally the original melody was played again. Listen to Tommy Dorsey's Marie for an illustration. As Swing matured and diverged from jazz, the bands' arrangers became more important. Jazz of course relies heavily on improvisation, where performers take a simple melody and invent their own variations as they play. Often no two performances of the same song would be the same. With Swing, however, more and more of the parts would be written down and played as written. For one thing, while it's easy for a small combo to sound cohesive even while the musicians improvise, it's a lot harder for 15 or so performers to all do their own thing! It's the arrangers' job to take the melody and decide what instruments would play what parts, and how they would blend together as a group. At the same time most arrangements had "open" sections where an individual player would still be able to improvise a solo. Dorsey's Marie is again a good illustration, with Bunny Berigan's famous improv solo about 2/3 of the way through the recording.
Arrangers also helped each band achieve a distinctive sound by incorporating similar techniques into each performance. That let orchestras in effect "brand" themselves so that even without having a tune announced on the radio, listeners would almost immediately know what band they were hearing.
Later in the Swing Era arrangers effectively dominated the genre, with solos and improvisation playing a lesser role. Several orchestras - Harry James, Tommy Dorsey, Artie Shaw, and Glenn Miller to name four of the most prominent - even added string sections and played expansive, heavily-arranged songs that veered in the direction of pop music, while still retaining some jazz flavor. There are many thousands of excellent web sites that feature Big Band music from the 1930s up to today. See the Related Links below for a very small selection.