Wiktionary
n. 1 The essence of what it means to be a rock; the quality that make a rock what it is. 2 (context slang English) The quality of music being rock music, or generally "rocking" (being excitingly good).
Wikipedia
RockNess was an annual music festival which took place in Scotland at Clune Farm, Dores, on the banks of Loch Ness near Inverness in the Scottish Highlands. The first Rockness festival took place on 24 June 2006 and continue to grow in size every year until 2013, which was the last running year of the festival. In June 2008 AEG took over as the main promoter of the festival. The festival was known as "the most beautiful festival in the world" and "the only festival with its own monster" due to its scenic location at Loch Ness which is the alleged home of the cryptozoological Loch Ness Monster. Despite the festival's name it was not solely a rock festival but presented music from all genres, especially mainstream and electronic music.
The festival was last held in 2013, with the 2014 & 2015 editions being cancelled in advance.
Usage examples of "rockness".
Farther south there was the Rockness, where streams cut through stone to the water.
And there were places where the shape of the Rockness conspired with the sounds.