Tatum is noted for his chord substitutions - that is, replacing one or more of the chords in a progression with other, different chords, thereby altering the original harmonic flavor of the progression. Week 4 Notes

In 1924 Louis Armstrong left King Oliver's band in Chicago to join Fletcher Henderson's in New York. Armstrong returned to Chicago to lead his own band, soon to make his deservedly famous Hot Five and Hot Seven recordings. Henderson and his sidemen, for their part, had absorbed the essence of solo improvisation and swing from Armstrong. Fletcher Henderson was a pioneer in the emerging jazz style that would come to be known as swing. His arrangements - or charts , as they are called - provided the model for most of the bands that would come to prominence in the latter half of the 1930s. Henderson's charts divided the band into three sections:  Reeds: alto, tenor, and baritone saxophones  Brass: trumpets and trombones  Rhythm: piano, guitar, double bass, and drums Henderson would pit the reeds against the brass in a call-and-response that later became a hallmark of the big band style. (This back-and-forth between sections is also described as antiphonal counterpoint .) Don Redman was a conservatory trained saxophonist / composer who was hired by Fletcher Henderson. His arrangements not only heightened the distinction between written and improvised sections, but also made skillful use of the contrasts between reeds and brass - the innovation that Henderson's orchestra became known for. He was also among the first to develop the voicing across sections technique, where players are drawn from the various sections to play a line together. Benny Goodman was a big band leader and clarinetist who benefited greatly from his association with Fletcher Henderson and his use of Henderson's arrangements. Goodman's band was one of the few white bands regarded as "hot" by black jazz musicians More than any other individual, Goodman popularized "swing" for the broader American population, ushering in the era of jazz's greatest popular appeal. He became known as the "King of Swing" due to his unparalleled success in the mid-to-late-30s. He had the uncanny ability to please the public with hit after hit, as well as keep his musicians happy by maintaining high level improvisation as a regular part of their performance practice. Goodman recognized the merits of African-American jazz and championed its musicians. In a racially segregated America, Goodman crossed the color line by hiring African- Americans to play in his combos. Charlie Christian was the first great electric guitarist in jazz, and he was highly influential on the guitarists who followed him. His flame burned brightly all too briefly, though, only to be extinguished by poor health aggravated by hard living. He died of pneumonia in 1942 at the age of 25.

Lionel Hampton was among the first to play the vibraharp, a xylophone-like instrument with resonator tubes suspended below the bars to create a natural reverberation of the sound.