I was in the audience:)
The rap star and former member of Public Enemy turned reality show star is "Flava Flav" and his show is Flavor of Love.
The piece was filmed at the magic castle on a normal night this past spring.
It was unannounced. The bit you saw with Flava Flav and magician Chase Curtis was not part of the actual show. It was a surprise "pre-show" add on to the beginning of the early Palace show. After the filming the actual show started.
The whole filmed segment was a reality-show bit and the whole filming lasted probably 10 minutes at most. Before the filming Flava Flav was introduced to the crowd which gave him a huge round of applause, even tho more than half the room, mostly those over 40 years old, had no idea who he was. Tho many knew him from this reality show. Granted, his target market audience is not the suit and tie regulars at the magic castle.
No one was expecting much in magic with the segment and in person there, the audeince seemed very cordial, but alot of the look of confusion you speak of might be from the fact that everyone was unaware this filming was taking place and were expecting the normal show schedule. They probably didn't know what to expect next.
The magic castle frequently is used as a filming location. Its a popular LA legend and is a great income producer for the castle to allow filming. For instance, there is a recent music video entirely filmed at the magic castle. Search the internet for it.
If you want to know more about the Flava Flav night, there is a write-up on the surprise filming at: http://magic.about.com/od/magicinthemed ... flavor.htm