Thursday night, a legendary Chicago voice will honor two other singing greats: Otis Clay will pay tribute to Mahalia Jackson and Sam Cooke. The concert is part of the Made in Chicago: World Class Jazz series at Millennium Park. Clay came to WBEZ's Jim and Kay Mabie Performance Studio Wednesday to talk--and sing--some gospel and soul; he was joined by Dedrick Blanchard on piano. They started with the classic gospel song Soon I Will Be Done With The Troubles of The World. Full disclosure: WBEZ is a media sponsor for the Made in Chicago: World Class Jazz series.