To make up for the unfinished Fugue Bach concluded the work with a Choral Prelude upon the tune “Wenn wir in höchsten Nöthen sein,” which he dictated to his son-in-law, Altnikol, a few days before his death.(252) Of the extraordinary skill it displays I do not speak, save to remark that even in his last illness it proclaims Bach’s skill undiminished. The pious resignation and devotion that characterise it move me deeply whenever I play it. Nor should I find it easy to say which I had rather had been omitted, the Choral Prelude, or the conclusion of the unfinished Fugue. 9. Lastly, after Bach’s death, his four-part Chorals were collected by his son, Carl Philipp Emmanuel, and were published by Birnstiel (Berlin and Leipzig), Part I. in 1765, Part II. in 1769.(253) Each Part contains one hundred Chorals, mostly taken from the composer’s church Cantatas. More recently Kirnberger edited, in four volumes, a collection of Bach’s Chorals. They are published by Breitkopf.(254) Bach’s works, still in MS., consist of compositions for the Clavier, Organ, with and without other instruments, Strings, and the voice. I will enumerate them in that order. I. Compositions For The Clavier 1. _Six Little Preludes far Beginners_.(255) 2. _Fifteen Two-part Inventions_. An Invention is a musical theme so constructed that by imitation and inversion a whole movement can be evolved from it. The subject having been first stated, the rest develops naturally out of it. For the instruction of a young Clavier player these fifteen Inventions are of great value, seeing that the composer has been careful not only to provide exercises for both hands but for every finger as well. They were composed at Cöthen in 1723, with a long title which begins: “An honest Guide, in which lovers of the Clavier are shown a clear method of playing correctly in two parts,” etc.(256) It cannot be denied that, among other blemishes, the Inventions occasionally exhibit melodic poverty and roughness. But finding them useful to his pupils, Bach eventually revised them and removed from them everything that offended his maturer taste, so that they now stand as masterpieces of pure music. Moreover they are invaluable exercises for the fingers and hands and are sound instructors of taste. There is no better introduction to Bach’s larger works than they afford.