Five acts, all jazz headliners, in 3 hours at the Jazz Foundation of America’s Loft Jazz Party, plus Chicago drummer-composer Mike Reed’s thrilling People, Places & Things quartet and alto saxist Darius Jones’ trio at Drom in the East Village — bountiful blues, soul, swing, groove, creativity, tradition, big names and newcomers in NYC on Saturday and Sunday. It’s like this all the time in the jazz capital of the universe, but good not to take it for granted.