A week after the cancellation of three Taylor Swift concerts in Vienna due to a feared terrorist threat, the next major musical event in Austria is under special police protection. For the four-day Frequency Festival in the city of Sankt Pölten, security measures have been further intensified despite no specific terrorist alert, said Interior Minister Gerhard Karner. The top act on the first day is the British singer Ed Sheeran. Undercover officers are also said to be present in the audience. Additionally, special units have been strategically positioned to intervene quickly if necessary, Karn…