Back in the days when all British regiments had bands it was common for the band to entertain the locals with outdoor concerts in park or seaside bandstands.  As well as the usual martial and patriotic fare, such concerts often featured suites drawn from operettas or operas; both old and new.  Shortly before the First World War the more than averagely enterprising bandmaster of the Grenadier Guards made such a suite from Richard Strauss’ Elektra (premiered 1909).  Rather pleased with it, he decided to insert it into one of those rather dull pauses that happen during Trooping the Colour.  The bandsmen were also rather pleased with themselves for executing such advanced music.  Unfortunately they were soon to be deflated as a liveried flunkie emerged from the palace with a message for the bandmaster… “The King does not know what the music the band just played was but it is never to be played again”.  Sic transit gloria mundi.  Mozart apparently is OK though as the Coldstream’s slow march to this day is Non più andrai.