The Land of the Mountain & the Flood, by Hamish MacCunn

From Wikipedia:

The Land of the Mountain and the Flood is an overture for orchestra, composed by Hamish MacCunn in 1887. Often cited as the archetypal Scottish overture, it is frequently likened to the works of Sir Walter Scott in its unashamedly lyrical, romantic view of the Scottish landscape. The title is in fact taken from Scott's The Lay of the Last Minstrel, canto vi, stanza 2. After its first performance at Crystal Palace, George Bernard Shaw said witheringly of it:

Mr MacCunn’s Land of the Mountain and the Flood, a charming Scotch overture that carries you over the hills and far away, was much applauded. I object, by the bye, to the “working out” section, which Mr MacCunn would never have written if his tutors had not put it into his head. I know a lady who keeps a typewriting establishment. Under my advice she is completing arrangements for supplying middle sections and recapitulations for overtures and symphonies at twopence a bar, on being supplied with the first section and coda.

In the 1970s it enjoyed renewed popularity as the theme for the BBC television series Sutherland's Law.