The wonderful power of Mozart as a composer is never more clearly revealed than in the production of that strangely mysterious effect which, unaided by any mere external text or programme, is here and there to be found in the works of all the really great composers. It may be illustrated by even so familiar an example as the fifth bar of Beethoven’s No. 3 Leonora Overture, where the downward C major scale ends on F♯, and is followed by the unexpected and weird harmony of that note. Other instances may be found in the scherzo of the Fifth Symphony of Beethoven, and in Schubert’s Lebens-stürme, op. 144, where the chorale-like subject enters. Wagner, too, has many examples in the instrumental portions of his works; for instance, the commencement of Scene 4, Act ii., of _Die Walküre_. The opening of Mozart’s Quartett No. 6 in C major, which has already been quoted on page 60, has sometimes been referred to as illustrating this mysterious kind of effect; but, while the passage is unquestionably peculiar, there are others which better exemplify what is meant by this atmosphere of “other worldness,” as it has been called. Take, for instance, the passage beginning at the forty-second bar of the first movement of Quartett No. 2 in D minor of the set dedicated to Haydn, and mark the subtle effect in bars 4 and 5, especially the sudden change from forte to piano at bar 4, and the double piano which follows:— [Music: MOZART.] Of course it must by no means be overlooked that it is only by a perfect rendering of the music that ideal effects of this kind can be revealed as they first arose in the mind of the composer. As illustrating another and quite different kind of effect, we have in the andante of No. 8 Quartett in D major, dedicated to the King of Prussia, an example of pure and simple melody, which, without subtlety or mysticism, flows on in calm, unclouded beauty. [Music: MOZART.] [Sidenote: =Mozart’s other Chamber Music=] The earlier String Quartetts of Mozart are not of equal merit with those which he composed some nine years later. Of these the six dedicated to Haydn are quite remarkable, as are also the three dedicated to the King of Prussia. In these three the ’cello (the King’s favourite instrument) is more than usually prominent. The Quartetts for flute and strings and those for oboe and strings are unimportant, but that for clarionet and strings is a more worthy work. Of the String Quintetts those in C, G minor, and E♭ are the best, especially the G minor, which is truly great. Mozart doubles the viola in these Quintetts. It was the custom of his contemporary Boccherini, to whom reference has been made, to double the ’cello.