Bartok used the arch form quite often in planning his multi-movement
structures.  Those where he uses it include the Concerto for Orchestra,
String Quartets #4 & #5, and the 1st Suite for Orchestra.

Used within a single movement it could be considered an expansion of
the ABA form, where the BCB in the ABCBA arch could constitute the middle
section.  Vaughan Williams consciously did this in the slow movement of his
5th Symphony.  It doesn't seem quite kosher to use the term arch if the C
section is the same (or at least a variation of A), as it is in inter alia
Beethoven's Heilige Dankgesang (in opus 132) or the slow movement of
Bruckner 7.

Aaron J. Rabushka
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