The Symphonic Poem "Isle Of The Dead" Opus 29 was written in 1908 and was inspired by a painting titled Isle Of The Dead by the Swiss artist Arnold Böcklin that he saw exhibited in Paris in 1907. The painting depicts the ancient Greek myth of the newly dead on their way across the river Styx that separates the land of the living from the land of the dead.
Rachmaninoff begins the piece with a time signature of 5/8. The resultant rhythm may represent the rhythm of the oars in the water as Charon, the boatsman of the myth rows the boat to the land of the dead. In the beginning, Rachmaninoff beats this 5/8 time signature as 1-2-3-4-5, with emphasis on the first beat and the third beat. This breaks it down into essentially alternating bars of 2/8 and 3/8 time. He then shifts the beats into 1-2-3-4-5, and further along he has a section that shifts the beat to 1-2-3-4-5.
This shifting within the beats of the 5/8 time signature is very subtle and it is one of the many many details of this master work that helps give the impression of bleakness, loneliness and tension that leads to the climax of the composition, and its denouement. To add to the effect, Rachmaninoff includes the ancient Latin hymn Dies Irae (day of wrath), a hymn thought to have been written in the 12th century and was part of the Roman Catholic Requiem Mass.