London Grammar Pull Out Of Unknown Other | Friday 16th August 2013 | Christina London Grammar Pull Out Of Unknown Unknown Festival recently announced that the art rock trio London Grammar have had to cancel their appearance at this year's festival due to 'album commitments.' Theme Park will take their place on the festival line-up as will the solo electronic pop singer Pawws. They will join the likes of Django Django, Disclosure, Clean Bandit, Cyril Hahn, Julio Bashmore and many more great acts. Unknown is set to be fun in the sun this summer. Christina Hirst