Go to http://www.pbs.org/wttw/soundstage/bbking/bio.html and click on "Video."

Here in the U.S., PBS stations will begin airing the episode of Soundstage with BB King this weekend. The date/time varies greatly depending on the station. (For example, here in Atlanta, the new season of Soundstage won't start until February 7, and the BB King episode is the 4th one of the season. Hopefully I'll get it on February 28.) There's a link on the website which will allow you to check the schedule for your local station.