The composition of this work in short
The rectangle 3x4
The duo is inscribed into a rectangle width 4 (terrestrial) by height 3 (celestial). The diagonals are the complementary side of the triangles 3-4-5.
The rectangle makes a cross by turning 90°. The inscribed circle diameter 2 fits with the both personages, but they are separated in spite of the
link of their instruments. This 2 means here difference.
The mandorla of circles 3
The circle diameter 3 brings a resolution, by a mandorla involving a double square in its almond. The blue rectangle, on the right, has a silver
ratio = (1+√2)/2, for a width of 3/2. This indication is given on the silver saxophone...
And the celestial 3 tames the duality of the 2 !