Jazz music made its mark in the hearts of Americans ever since the 20th century when people embraced the musicians of the time. However, when the singers came on the scene strong with skills in the art of scatting that is a vocal form of Jazz improvisation, the ability to articulate music expressively, and have that pizzazz to swing to the rhythms effectively makes a Jazz virtuoso. Jazz music bore another gift on the American public to spread to the world during the 1940's when singers came together to form groups. The sound of acapella harmony of many voices like in a church choir using a juxtaposition of Jazz harmony is ethereal and divine.
In fact, due to the success of such groups as the Mills Brothers, Boswell Sisters, Andrews sisters, and Modernaires during the 1930's 1940's made Jazz fans of vocal Jazz music seek more. As a result, record stores stocked up on the music of vocal Jazz music, and it became a tremendous success that made quartets like Manhattan Transfer a household name today.
In addition, America has the largest selection of vocal Jazz music even though there are vocal Jazz ensembles all over the world. These new vocal Jazz groups do not all sing a capella style music that is common to barber shop. Vocal Jazz groups commonly use a Jazz band to accompany them as they perform. Jazz music may not be as strict as classical music, but it is in a class all it's own. It takes great skill to sing Vocal Jazz as it does with Classical, and many other styles of music. Meaning, everyone cannot be a good jazz soloist, but it doesn't mean that they cannot sing in the vocal jazz ensemble. Each singer must match in volume, resonance, and key in order to be a worthy member in the vocal Jazz ensemble. Ever singer must be able to sing their parts, and be heard as well as blended into the group. There are times when different people in the vocal Jazz group will be asked to scat to the music, and take the challenges that some complex Jazz music holds with great skill.
All the beauty that Vocal Jazz possessed in the past did not always keep it in popularity. For instance, there was a time in the 60's when Jazz music no longer had mass appeal due to the American interest in Rock music. Imagine the record companies who supply music to the radios, and the nightclubs who allowed popular acts to perform live suddenly locking Jazz musicians out. Yet, Jazz never lost its following despite the ever-changing interests of the public. Vocal Jazz singers attempted to begin again in the 70's, but the public did not show much interest in a style that was considered passé.
Fortunately, those who loved the music and dedicated themselves to the music caused people to take notice from the latter part of the 80's to the millennium where Jazz singers came prepared to recreate Jazz again. Vocal Jazz singers went along with the times to keep the traditional Jazz and add new elements that the public would like to hear.