Fontana Mix...

Dear all,

I have trouble understanding John Cage's Fontana Mix instructions:

Cage writes: "Measurements vertically on the graph with respect to the intersections of the curved lines and the straight line may specify actions to be made. Thus, in the case of (Fontana Mix) tape music, the thickest curved line may give sound source(s) where the latter have been categorized and related quantitatively to 20. (In this case the 2 points connected by the straight line must permit the latter to intersect the thickest curved line.) Intersections of the other lines may specify machines (among those available) for the alteration of original material. Amplitude, frequency, overtone structure may be changed. Loops and specific durations introduced." 

Does Cage mean to ONLY pay attention to the values measured at the intersections between the straight line and the curved lines within the graph? Do only values at the intersection determine parameter settings, or do the values constantly change, following the curves?

If i.e. a volume curve crosses the straight in the 30th and the 50th field; does this mean that the volume is set to same value for 20 fields, namely the value  measured in the 30th field? or do the parameter sttings/values always also follow the movement of the curves? 

Maybe the answer depends on the time bracket that the graph describes, i.e. if the total graph represents 30 seconds, and each field is merely a third of a second, then we use values measured at the intersections only; but if the graph represents 300 seconds, with each field being 3 seconds, then we have time enough to follow the movement of a line?

it seems so pointless to disregard the graphic impression that the score gives as a whole (with beautiful curved lines and dots).... but then again it also appears that the dots only have meaning for the placement of the straight line (timing) and have no other influence on any other aspects or actions within the piece... 


what am I overlooking or misunderstanding ?

thank you for taking the time.


best
anne