The misty seascape embodied in Mendelssohn's surging overture

The Hebrides, also called Hebrides Overture or Overture to the Lonely Isle, is an orchestra piece by Felix Mendelssohn, a tempestuous early work inspired by his visit to the Hebrides islands. 

While on a ferry voyage, Mendelssohn was so struck by the misty scene and the crashing waves that it gave birth to a melody as fierce as the surge and power of the sea itself.

He wrote to his sister Fanny, describing the experience and including a few bars of the tune that he would later use at the beginning of his overture:

The main melody creates a sense of unity throughout the work despite being presented in different voices and timbres. 

Here is the unsurpassed performance of this piece by the Berliner Philharmoniker, with Herbert von Karajan conducting: