Organisers say the festival’s silver anniversary edition, external reflects both its international reputation and its long-standing connection to the city’s live music scene.
Curtis Stigers performed in the city earlier this week, so too Donegal blues guitarist Muireann Bradley.
Leo Richardson, Guy Davis and Sylvie Noble are also among those playing the festival this year.
Scores of venues across the city play their part hosting the festival, including the Millenium Forum, New Gates Arts Centre and The Playhouse.
Bars and pubs too will be filled with music lovers, while a central feature of the festival is the scale of free events.
Brass bands will roam the city’s streets, al fresco jazz hosted in the craft Village, while Guildhall Square’s Gay McIntyre stage will host open air jazz for the next three days.