Just what distinguishes them from earlier works for the pianoforte it is not easy to say exactly. The form, for one thing, seems new. They are for the most part short, often not more than two pages long. They consist of three sections, a long flowing melody, a contrasting section which is for the most part melodious too, and a return to the opening melody, commonly elaborated. There is in most of them a little coda as well. Most short pieces of the day, and even of an earlier time, were in the well-known forms of rondos or simple dances, from which these are obviously quite distinct. But as far as form goes they are not very different from the aria, except in that the middle section generally maintains the accompaniment figures of the first section and essentially the same mood as well, so that there is little appreciable sense of demarcation. Other short pieces to which one looks for a possible origin, such as those of Couperin and the preludes of Bach, are far more articulate and far less lyrical. The sonatas of D. Scarlatti and the Bagatelles of Beethoven are mostly pieces in two sections, each repeated. The same is true of the _Moments musicals_ of Schubert. In the nocturnes of Field no distinct feature of form is obtrusive. The intellectual element is wanting. There is no attempt at crispness of outline, or antithesis or balance. They seem to be an emanation of mood or sentiment, not a presentation of them. Hence they represent a new type in music, one which has little to do with emotions or ideas, with their arrangement or development, but lets itself flow idly upon a mood. In style they are wholly lyrical. The accompaniment is usually monotonous and unvaried, but always flexible. Here, then, one looks to find the Alberti bass; and here it presents itself most clearly in the second stage of its development. The harmonic stream on which the melody floats along is a series of chords broken into their constituent parts so that they may be kept in a constant and gentle vibration. But, whereas the Alberti bass in its first stage was a device applied to the harpsichord and for that reason was always close within the span of the hand, here in its second stage, now adapted to the pianoforte, it has been expanded. The pedal can now be counted upon to blend the relatively wide figures into one harmonic whole. Therefore, instead of the original close grouping, we now find this wider one: [Illustration: Music score] This is no original invention of Field’s. Beethoven, in the sonata opus 90, wrote figures like this: [Illustration: Music score]