Jazz is a unique music style in a way because you can combine a number of jazz musicians and they will be able to immediately play together. This is perfect for events since this gives you the opportunity to customize the band for each specific occasion.
For example: Shall it be background music or do you want the music to take more focus?
A singer generally gives a more concert "feeling" than an instrumental band.
Small event? Maybe a duo is enough?
Jazz also has many sub genres. Here are some:
Old classic jazz
We are happy to help you find what suits your event the most!