The basic model The first question for the practising performer is, what does 'more or less' mean? The encouraging answer is that, in answering the question for oneself, one suddenly has access to a wide range of expressive devices. The 'lightest' application of the rule leads to a sostenuto, a sung phrase elegantly begun and ended (haven't we all struggled to express this verbally in some way to our students?), while the heaviest results in a powerful accent with the maximum space created for other material to be audible. Most of the time something in between will be required, from smooth elegance and tranquillity, say, to a bouncy giocoso. It is worth noticing that, for a performer, to require the answer to such a question is a powerful musical stimulus. The open-endedness of the demand is actually an advantage. One way to characterize excellent performance is as a sequence of flexible answers to a series of context-driven questions. Without this quality, playing becomes mechanical. When we consider a sequence of phrases, the advantage of the model becomes more apparent. We may range across the spectrum from separation, through contiguity and into sostenuto, while still retaining the autonomy of the individual phrases, just as we can with words when we speak. Our ability to do this is very important. Any method of showing phrasing that does not allow both separation and sostenuto as limiting cases is bound to fail in classical music of any subtlety, because the simultaneous and delicately balanced expression of both unity and diversity is fundamental. We need to be able to show both the sea and the waves, from storm to calm, with all the infinite variety in between. The wave/sea analogy is a good one for many purposes. It doesn't quite capture the structure of the model, though, because it doesn't yet include the idea that a phrase generally has the property of being beginning-oriented. (I choose this terminology to point up the distinction between phrases and 19th-century paraphrases, which, it will be remembered, are end-oriented.) Another pictorial analogy may help us: it is important to make sure we understand how the rule constrains in one sense, but yet offers sufficient flexibility, with the added advantage of clarity and structural similarity on different time-scales. The analogy is between the possible shapes of a phrase and the possible shapes of a simple leaf. Such a leaf is almost always broader near its base than at its tip, and there are many different shapes of leaf. Some are long and thin, some are broad and short. But some are broad and long, too, while others are thin and short. There is a variation in how broad the base of a leaf is, and also, passing along the leaf, there is a variation in how quickly the broadness at the base yields to the delicacy of the tip. Phrases have this same quality as they develop in time. They begin and end elegantly, and have a variety of possible shapes within a general conformity. What in the phrase corresponds to greater breadth in the leaf, though, may be more complex, and it is unwise to attempt to characterize it in detail. Warmer, more energetic, brighter, louder, more insistent or more stroked are a few ideas to be going on with, but by no means all of these would be appropriate to any one particular phrase. Looking at a sequence of phrases, and the corresponding sequence of leaves in the analogy, there is no natural way of joining one leaf to another, allowing a modelling of the sequence of phrases that represents simultaneously both continuity of sound and beginning-oriented shape. This is because the 'leaf' analogy is missing the important idea that a phrase can occur at different basic dynamic levels, or different brightnesses of basic timbre. After all, a leaf begins and ends with nothing. On the other hand, waves on a calmish sea don't begin and end with nothing, because they can occur on deeper or shallower seas. So they have shape and continuity; but unfortunately not necessarily the leaf-like, beginning-oriented shape we require! We have to combine the two pictures, and imagine a wave whose profile is like one side of a simple leaf, occurring on a sea whose depth may vary. This analogy has the advantage that the phrase structure is explicitly yet not crudely represented. In particular, such a wave would embody naturally Leopold Mozart's 'small if barely audible softness' just like speech, which is in general continuous, yet perceptually segmented. For those who prefer a non-visual metaphor, a highly suggestive tactile analogy of a beginning-oriented structure in our constant experience is that of taking a step. The changing sensation of pressure or weight on each foot as we take slow steps has just the structure I have been describing. And of course, music, especially classical music, is often said to dance, or need to dance. When it dances, phrasing is one of the (three) drums it dances to. It is exactly because the shape of a simple leaf is recognizable as an example of one basic structure, regardless of its scale or type, that it is a useful analogy for a simple phrase. Simple, normal phrase-structure needs to be unambiguous, so that a sequence of phrases may be recognized as a rhythm. If everything is a special case, there is no perceptible rhythm. Moreover, only thus does a more radical, non-rhythmic variation of form have meaning. This is merely a special case of a general principle that applies to all the arts. Structures containing the same shape repeated at different scales, and being transformed in other ways, were discussed in D'Arcy Thompson's famous book On growth and form. He showed that the situation occurs in nature to an extent that makes it surely unsurprising to us that it should be a powerful expressive device in art. Moreover, it constitutes a very natural background against which events of a different shape, should they be required, may be set in relief. A very suggestive way of looking at the situation for players is that when the music has a particular character, and there are phrases of different length that constitute a particular line of it, all the phrases may easily have the same shape: we allow the short ones to change from weight to lightness faster, because their time-scale is shorter. This is like having leaves of different sizes, but all from the same plant, and not surprisingly has the effect of retaining the same character throughout the passage. This character can then change immediately or progressively, at choice, to another character appropriate to the next passage. (Of course, such a unified character may not always be what is required  but it often is.) This way of playing also gives a natural variety of attack and emphasis that may mean that we don't need to do any more (by making, say, one phrase heavier or lighter than the next). The varying rhythms are already sufficient. The setting of shorter phrase shapes against longer ones in different lines is then inter alia a device to allow both to be heard. Also, making the shapes by adding sound at the beginnings of each of a sequence of shorter phrases increases the energy of a passage, while the contrary process of lightening the ends has the opposite effect. We can think of having deeper or shallower waves of the same length. Alternatively the following analogy might help: if we imagine beginning with a horizontal cylindrical rod, the length of the phrase, we can sculpt it into a phrase-like shape by carefully adding clay, mostly towards the left-hand end. On the other hand, we could create a leaner version of the same shape by cutting away material from the rod itself. The traditional wind markings (pencillings) in modern performances (fortepianos on all held chords) also become redundant. A wind or brass section will naturally regard a long note as a simple or degenerate phrase, and lighten it to allow the melody to be heard. The melodies themselves are better heard anyway. It doesn't take much investigation of a Mozart opera to realize that many vocal entries are organized to take advantage of the ends of phrases in the orchestra, when there will be less substance to the sound. 'Difficult' pieces for balance such as the Grand Partita for winds and double bass, where the basset horns often need special consideration, yield simply to the formula that all the members of the group habitually phrase in this way. The technique often employed by Mozart of writing different phrasings for different instruments in one passage, which later editions often 'rationalize', is seen as a subtle textural variety (analogous to brush-strokes in a painting) that is much more appropriate to the music than the modern tendency to add surface interest using vibrato.