In 1829 Mendelssohn accepted an invitation from the Philharmonic Society in London to visit England. He then toured the country, moving towards Scotland where he began work on Symphony No. 3 in A minor which is called ‘The Scottish”.
During this time he also visited the Hebrides and wrote to his sister Fanny that he was deeply affected by it. Originally called ‘The Lonely Island”, he wanted to depict the effect of seeing the isle of Staffa, and Fingal’s Cave (see it here).
Whilst called an overture, we could call this one of the first tone poems. He sent a sketch for the opening cello/bass line in a letter to his sister in August 1829. It’s scored for double woodwind, two horns, two trumpets, timpani and strings.