Chicago is widely regarded to have been the most happening jazz city for a while, although London (see post above yours) is beginning to steal attention.
Still going strong at 77. He played the BAJF at St Luke's Church just a few months ago and was as special as ever.
If you don't know it, try Mats Gustafsson's stuff, The Thing, Fire! and Fire! Orchestra especially.
They're staggeringly good. Moses is playing at the Brighton Festival this year.
Sons of Kemet are well worth a go if you like this. Artefacts by Black Flower is somewhat underappreciated too.