The wave of composition of the early 1870s was followed by a period of revision, beginning with the completion of the first draft of the Fifth Symphony in May 1876 and ending with the commencement of work on the String Quintet towards the end of 1878 (the third Finale of the Fourth Symphony dates from 1880, but can be considered as belonging in spirit to this process). The revisions encompassed the first five numbered symphonies and the three great Masses, original composition meanwhile continuing in a more modest form with three secular choruses and the motet Tota pulchra es Maria. While Bruckner’s ultimate aim was to achieve forms that were more cogent, clear and dramatic, his immediate concern was to regularize periodicity, an aim achieved by copious small-scale alterations. The greater aim is served by the lesser, for by stabilizing the basic metrical units of the musical discourse, and transferring the tensions that result from uneven phrasing to a higher structural level, Bruckner exerts a stronger control over rates of harmonic change. The resulting clearly differentiated levels of harmonic stability have implications for the projection of form.