Today's baseball match between Washington Nationals and Florida is being broadcast on Z104 radio station, which has a 'listen live' facility via Real One Player and Windows Media.
The General Director of the Washington National Opera will sing the National anthem during the opening pitch and God Bless America during the "seventh inning stretch" (whatever that is). The broadcast begins at 1.05pm ET which is 6.05pm BST. An hour or two later in continental Europe and possibly five o'clock in the morning in New Zealand.
TotalRecorder is already on standby and I've put in a request for assistance to find out when the opening pitch and seventh inning stretch are likely to occur...
For four dollars you can even watch it on your PC...
Update: Well, I found a picture, anyway...