not very obvious reason, being excluded. For the sake of completeness it should be mentioned that Litolff's so-called Concerto-Symphonie in E flat, for piano and orchestra, has exceptionally a scherzo as the third of four movements.
The first movement in Mozart's concertos always begins with a tutti passage for the orchestra, in which the principal subjects are announced, much as in the first part of the first movement of a sonata. Sometimes the 'second subject' is omitted in this portion of the piece, but it is more frequently introduced. An important difference in form, however, is that this first tutti always ends in the original key, and not in the dominant, or the relative major (if the work be in a minor key), as would be the case in a sonata. The solo instrument then enters, sometimes at once with the principal subject, and sometimes with a brilliant introductory passage. A repetition, with considerable modification, of the first tutti mostly follows, now divided between the principal instrument and the orchestra; the second subject is regularly introduced, as in a sonata, and the 'first solo' ends with a brilliant passage in the key of the dominant (or relative major, as the case may be). A shorter tutti then leads to the second solo, which corresponds to the 'Durchführungsatz,' or 'working out' of a sonata, and which, after various modulations, leads back to the original key. The principal subject is then re-introduced by the orchestra, but in a compressed form, and is continued by the soloist with the 'third solo,' which corresponds in its form to the latter part of a sonata movement. A short final tutti brings the movement to a close. In most older concertos a pause is made, near the end of this last tutti upon the 6-4 chord on the dominant for the introduction of a cadenza by the player. Though very general, this custom was by no means universal; in several of Dussek's concertos—notably in his fine one in G minor, op. 49—no such pause is indicated. The cadenza, when introduced, could be either improvised by the player, or previously composed, either by himself or by some other person. Mozart has left us thirty-five cadenzas written for various concertos of his own, which, though presenting in general no very great technical difficulties, are models of their kind. Beethoven has also written cadenzas for his own concertos, as well as for that by Mozart in D minor. In the cadenza the player was expected not merely to show off his execution, but to display his skill in dealing with the subjects of the movement in which it was introduced. A cadenza consisting entirely of extraneous matter would be altogther faulty and out of place, no matter what its technical brilliancy. It was the invariable custom to finish the cadenza with a long shake on the chord of the dominant seventh, after which a short passage for the orchestra alone concluded the movement. In older works the soloist was silent during these few bars; but in his concerto in C minor (Köchel's Catalogue, No. 491) Mozart for the first time tried the experiment of associating the piano with the orchestra after the cadenza; and his example was followed by Beethoven in his concertos in C minor, G major, and E♭.
Before proceeding to speak of the modifications introduced into the concerto by Beethoven and other more modern composers, it will be well to complete our description of the form as left by Mozart. The second movement, which might be an andante, a larghetto, an adagio, or any other slow tempo, resembled in its form the corresponding portion of a sonata. Sometimes the variation form was used, as in Mozart's two concertos in B♭ (Köchel, Nos. 450 and 456); but more frequently the ordinary andante or larghetto was introduced. Two charming examples of the Romance will be found in the slow movement of Mozart's concertos in D minor and D major (Köchel, Nos. 466 and 537), though the latter is not, like the first, expressly so entitled, but simply bears the inscription larghetto. The solo part in the slow movements is frequently of an extremely florid character, abounding in passages of ornamentation. Sometimes a cadenza is also introduced at the close of this movement—e. g. in Mozart's Concertos in A major (Köchel, 414), C major (Köchel, 415), and G major (Köchel, 453). In such cases, as is evident from the examples written by Mozart himself for the works mentioned, the cadenza should be much shorter than in the first movement.
The finale of a concerto was mostly in rondo form, though examples are to be found in Mozart of the variation form being employed for this movement also; see concertos in C minor (Köchel, 491), and G major (Köchel, 453). Sometimes this rondo was interrupted by a complete change of tempo. Thus the rondo of the concerto in C major (Köchel, 415), which is in 6-8 time, is twice interrupted by an adagio in C minor, 2-4; in the middle of the rondo of the concerto in E♭ (Köchel, 482) is introduced an andantino cantabile; while another concerto in E♭ (Köchel, 271) has a minuet as the middle portion of the final presto. Short cadenzas were also frequently introduced in the finales; the concerto in E♭, just mentioned, has no less than three, all of which, instead of being left to the discretion of the player, are, exceptionally, written out in full. Similar short cadenzas will be found in the rondo of Beethoven's concerto in C minor, op. 37, while in the finale of the concerto in G, op. 58, a pause is made with the special direction 'La cadenza sia corta'—the cadenza to be short.
The innovations introduced by Beethoven in the form of the concerto were numerous and important. Foremost among these was the greater prominence given to the orchestra. In the concertos of Mozart, except in the tuttis, the orchestra has little to do beyond a simple accompaniment of the soloist, but with Beethoven, especially in his later concertos, the instrumental parts have really symphonic importance. Beethoven was also the first to connect the second and third movements (see concertos in G and E flat), an example which was imitated by Men-