Date added: 13 Jun 2015
Before radios and telephones were used in the British army, regiments would communicate orders to each other by sounding a bugle. The reason this was effective was because it was quite loud, and different calls meant different things. Regiments that had a bugle would also need to have a bugler who would usually stay with a person of high authority to tell them when to sound calls.
Jonathan Leach's regiment may or may not have had a bugler but one of the buttons found from the uniform of a soldier in Captain Leach's regiment has the regiment number pictured with a bugle! Bugles were mostly used by cavalry, but if a lot of infantry regiments like Jonathan Leach's were advancing they would usually have had a band in front of the column. This would normally consist of trumpets, drummers and, if a Scottish regiment was advancing, a bagpiper. The reason they did this was to keep spirits up as many of the soldiers would be marching to their death.
Probably the most famous example of a bugle being sounded at Waterloo was the recall of the Scots Greys cavalry attack. Unfortunately they didn't hear it in time as it was only when the Duke of Wellington noticed the French lancers preparing to attack his cavalry that he sounded the recall. Although the Scots Greys did destroy a lot of French cannon and artillerymen, which was a very crucial and important task, it was paid at a very high price of British cavalrymen.