post-1868 use of Black Watch band/music tartan

[OC Richard]

I wonder why the two gentlemen in the front are laying down. Is there a significance to them being in the front, or is it just for general composition?

I guess they wanted the extra space to display those banners.

I think you're right, they wanted to show off the pipe banners.

Identifying the emblems on the banners would probably solve the question of which battalion of the Black Watch this is. (I'm not sure about the Black Watch but I know traditionally in at least some regiments those banners are the arms of the Company Commanders, the Captains, armigerous gentlemen.)

One of the men reclining in front is the Pipe Major, which is an interesting choice by him.

In photos of Pipe Corps the Pipe Major is generally at far left, which from the soldiers' perspective is far right, the Pipe Major's position on the march. (When the Pipe Major is giving commands to the band he prefaces them with "By the Right..." as in "By the Right, Quick March!")

Even here the Pipe Major assumes his customary position at front right.

I have no idea who these civilians are, an occasion sufficiently auspicious for the Pipe Major of the Black Watch to appear.