On Mozart 1: Mozart and recreative analysis 4
Ex.1: Mozart: Divertimento in D, K.136, first movement, bars 13–17
1. Arnold Schoenberg: Fundamentals of musical composition (London, 1967), pp.25ff. 2. Alison Latham, ed.: Oxford companion to music (Oxford, 2002), p.1137.
and both by Mozart’s time formulaic in the hands of an unimaginative composer, offer considerable scope for deviation in the hands of a Mozart.
The first of these two procedures is illustrated in ex.2. Here it is necessary to be clear that the terminology being adopted is that preferred by Schoenberg, since freer uses of the terms involved will be found in use. The eight-bar span appearing here is a period. It comprises two components, an antecedent and a consequent.
Simply put, Schoenberg’s definition may be summarised as follows.1 A period typically comprises two segments, each of four bars. The antecedent usually ends with a cadence other than a full cadence to the tonic. The consequent begins in a similar way to the antecedent but ends with a full cadence to the tonic. In ex.2 the crotchet upbeat to the antecedent becomes two quavers in the consequent. The next four notes of the antecedent are plainly repeated, but the C is shortened so as to bring forward the remaining notes (some decorated) leaving space for a full cadence to the tonic.
At this point the second of these two procedures must be introduced. Sequence has been simply defined as ‘The more or less exact repetition of a melody at another level, higher or lower.’2 (The original form of the melody is referred to as the ‘model’ when a sequence follows.) Sequence is therefore a productive, one might say progressive, way to vary a repetition, in that – if the diatonic integrity of the scale is honoured in the sequence – the quality of the melodic intervals will change. Thus in ex.3, which offers a notional sequential consequent to Mozart’s antecedent of ex.2, the tone from A to B in bar 1 becomes a semitone B-C in the sequence. That apart, there will also be harmonic consequences, further transmogrifying the model in both its essential identity and its effect.
Mozart himself often writes sequential consequents, a well-known one appearing in ex.4. Here the chromatic opening of the antecedent is developed in a sequential consequent one degree higher.