2. 5. Putting things together
We started our analysis presenting the three constitutive elements of the painting: the bars, the checkerboard and the background. Now it is time to put them together.
Despite their exterior aspect, bars and background share similar genetic principles (iterative construction) and similar formal elements (spiral motion and T-junctions). In addition they both refers to natural growing processes (of a branching plant or of a spiral shell) which Klee compares, just to state they share the same internal iterative structure.
What about the chessboard? In my opinion it constitutes the metric common trait, shared by bars and background, useful to connect and compare them.
Sketch 15 may help understand the statement:
Sketch 15
As for the bars in relation with the checkerboard are concerned, we already observed that the perspective horizon for the bars' system is the line separating in the checkerboard the first five rows of cells (starting from the low) and the three remaining. In addition look at the last bar (the smallest red one) which is placed exactly in the middle of the painting: just the checkerboard allows us to see it, while the asymmetric disposition of the bars (and the skewed perspective of the background) would deceive us.
Let us consider now the background in relation to the checkerboard. The perspective vanishing points are in symmetric positions with respect to the centre of the checkerboard; in addition the higher vanishing point lays on the horizon line of the bar system (similarly the lower lays on the line separating the first three rows of cells and the five remaining).
Hence the checkerboard works as a metric union trait between the main elements: bars and room.
Finally observe the blue spiral, starting from the right-upper corner of the painting. It is formed by seven consecutive segments, each of them (but the first two) corresponding to a side of the room; indeed, the guidelines for the first two segments are supplied by corresponding lines of the checkerboard as shown in Sketch 15: the first segment runs along the vertical line separating the last but one and the last column of cells, while the second segment of the blue spiral runs along the line separating the first and the second row of cells.