"In the Groove" by pianist and arranger Mary Lou Williams

Mary Lou Williams

Mary Lou Williams was an American jazz pianist, composer, and arranger. Williams wrote hundreds of compositions and arrangements, and recorded more than one hundred records...

 (born May 8, 1910) is a classic big band

Big band

A big band is a type of musical ensemble associated with jazz and the Swing Era typically consisting of rhythm, brass, and woodwind instruments totaling approximately twelve to twenty-five musicians...

 jazz

Jazz

Jazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...

 composition. The Kansas City

Kansas City, Missouri

Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

-based band Andy Kirk

Andy Kirk

Andrew Dewey Kirk was a jazz saxophonist and tubist best known as a bandleader of the "Twelve Clouds of Joy," popular during the swing era....

 and His Twelve Clouds of Joy gained brief national following largely through the efforts of its principal arranger, pianist Mary Lou Williams, who had a formative role in the Kansas City jazz

Kansas City Jazz

Kansas City Jazz is a style of jazz that developed in Kansas City, Missouri and the surrounding Kansas City Metropolitan Area during the 1930s and marked the transition from the structured big band style to the musical improvisation style of Bebop...

 tradition. The title gave wider currency for a jazz

Jazz

Jazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...

 musician

Musician

A musician is an artist who plays a musical instrument. It may or may not be the person's profession. Musicians can be classified by their roles in performing music and writing music.Also....* A person who makes music a profession....

's expression.