The African slaves were able to contribute to the elements of jazz are the following:
1. rhythm - It was a trait of African music to use 'polyrhythm' or the superimposing of a single rhythm
2. Blues - it is an important characteristic of Jazz that essentially evolved from the field hollering of the slaves
3. Syncopation - is also a critical part of Jazz because it varies the duration of the same notes being played in a song. This is also done by placing emphasis on beats (strong or weak).
This evolved from the call and response form used by the slaves when singing.