waves of blue heat that
wash the sky; sea-violins
play along the sands

Based on the poem, Blue Water, by John Gould Fletcher.
Sea-violins are playing on the sands;
Curved bows of blue and white are flying over the pebbles,
See them attack the chords—dark basses, glinting trebles.
Dimly and faint they croon, blue violins.
“Suffer without regret,” they seem to cry,
“Though dark your suffering is, it may be music,
Waves of blue heat that wash midsummer sky;
Sea-violins that play along the sands.”
According to Wikipedia, John Gould Fletcher (January 3, 1886 – May 10, 1950) was an Imagist poet (the first Southern poet to win the Pulitzer Prize), author and authority on modern painting.