Trite sentimentalism, Sherlock had said when John mentioned heading up to the Royal Edinburgh Military Tattoo. He didn't care though - something in the haunting lilt of the pipes and the rhythm of the drums stirred his Watson heritage and his army blood, and he decided he would go whether or not Sherlock came with him.
Unwilling to pass up a chance to visit another throbbing metropolis, or possibly unwilling to spend three days wallowing in John-less boredom, Sherlock ended up tagging along. He had spent the entire train ride alternating between making snarky deductions about their fellow passengers and pre-emptively complaining about the event they were planning to attend.
When they finally arrived, checked into the hotel, and settled in, Sherlock had graduated from irritating to insufferable and John threatened to lock him in the loo. Looking somewhat chastised, he shut up temporarily and they headed off to the grounds of Edinburg Castle to wander, relax, and indulge in the events. Unfortunately, Sherlock's silence didn't last long, and within moments he'd started griping again, spewing forth unpleasant comparisons to strangulated cats and sheep with various maladies.
John just smiled indulgently, focusing instead on the music and phasing out his blathering flatmate. Sonorous and booming though his voice may have been, even Sherlock couldn't compete with the wail of the bagpipes.