The Chicago Tribune's music critic contacted Jennifer Hudson's publicist to talk about the Chicago native's Super Bowl performance, which is still causing a stir.Jessica Kolstad, said this week that Hudson, 27, &quot;was singing live to a backing track. Her microphone was on, and she was singing live to the backing track at the request of the producers.&quot;But once the decision is made to use a backing tape, that's mostly what the TV audience hears. Only those around Hudson would have heard her live singing, the Tribune article says.Hudson and Faith Hill recorded their Super Bowl performances in advance. And, oh, so did Bruce Springsteen and the E Street Band. However, Springsteen's vocals were live.Read the Chicago Tribune article for more details.