Three men are doing a musical set with wires and equipment all over the stage, and they are holding unique guitar like instruments.
The three men were telling jokes on stage to entertain the crowd
The men can't be doing a musical set while telling jokes.
The men are either telling jokes, or doing a musical set with their guitar like instruments.  These are not usually the same thing
either the men are telling the jokes or doing musical set.  both cannot be done at the same time.