The cycle “Sonata of the Summer” was never exhibited during Čiurlionis' lifetime, and no information about the composition or general content of the work remains. The title of the series emerged in the catalogues of posthumous exhibitions, but all other available information was surrounded by the organizers' speculation and doubt.

“Allegro” depicts many small islands and sail boats reminiscent of Eastern junks scattered across a vast sea. The smoking alter on the main island is marked with the stylized initials of MKČ, and the bridges connecting the mountaintops are decorated with the initials of the artist's fiancée, Sofija Kymantaitė.

The peacefulness of “Andante” manifests itself through a distant landscape of fields, mountains, and the sea. A great oak tree supports the sky with its massive branches, while a village and its fields rest at its feet. Next to the huts stands a fantastical tower with heralds trumpeting good news to all four corners of the world.

The green-tinged “Scherzo” is characterized by improvisational lightness. It is full of light and unstoppable energy. The diagonals of swallows, butterflies, flowers, leaves, and flames fill the composition with joy, whereas the horizontal ornamentation of the gates emphasizes their dynamism. The interchange between the foreground and background creates the painting's multi-layered and polyphonic sound.

The kings of “Finale” rise through the clouds and send their blessings to a world beyond.