Who is considered one of the key figures in the development of bebop?

Charlie Parker is considered one of the key figures in the development of bebop due to his innovative approach to melody, harmony, and improvisation. He, along with other musicians, transformed jazz by moving away from the dance-oriented swing style to a more complex and nuanced form of music. Parker's virtuosic saxophone playing and intricate melodies set a new standard for improvisation, characterized by rapid tempos and sophisticated chord changes. His compositions, such as "Ornithology" and "Ko-Ko," exemplify the bebop style and have become cornerstones of the jazz repertoire.

In contrast, figures like Louis Armstrong and Duke Ellington were pivotal in earlier jazz styles, such as New Orleans and big band jazz, but they are not primarily associated with the bebop movement. Herbie Hancock, while an influential jazz musician, emerged later and is more closely associated with the jazz fusion movement. Therefore, Charlie Parker stands out as a defining artist of bebop and his contributions continue to shape the genre.