Trust chairman Luke Baldock said the festival had come a long way from its humble beginnings.
Organisers had changed things to make it a more diverse event.
``It is not just for the purist ... This is simply the continued evolution of it.
``This year will be all about bringing music into the streets. With so many free gigs the programme is designed to be accessible for all and aims to encourage the casual listener to enjoy the spontaneity of music.''
That includes performances in Arrowtown, Queenstown Village Green, Earnslaw Park and local pubs.
Another new event is MindJam, a collaboration with Catalyst Trust Queenstown and the University of Otago.
Mr Baldock described it as ``informal conversations covering a variety of big social topics''.
Ticketed events will still run and include a big band-themed ball, which is a fundraiser for the Wakatipu Youth Trust.
The new events would complement old favourites, he said.
``Forty years is a great achievement for any community event and the milestone provides a fantastic opportunity to celebrate the past and look forward to what the future might hold.
``There will be a really strong focus on pop-up performances that are not age or money restrictive. It is a broader music festival.''
Auckland four-piece band SoccerPractise had been named in the line-up,
and would be making its Queenstown debut.
Guitarist Leo Horgan described the band's music as ``unique''.
Tracks were created using a drum machine, strings and vocals with bandmates Thom Burton and Geneva Alexander-Marsters.
Once that element was complete Kim Newall added visuals.
``The big factor is Kim, who is a musician but is mixing live visuals. He has a camera, he has puppets, he has computer-generated algorithms that produce images that go in time with us to the music.''
Last year more than 80 musicians performed at almost 60 separate gigs including Kiwi and international jazz stars such as Nathan Haines, Italian jazz violinist Luca Ciarla and electronica hip-hop outfit Yoko Zuna.
Queenstown JazzFest starts on Friday and runs until October 23.