Rossini, Petite Messe Solenelle- Prelude Religieux

This movement from our set work is, as the title indicates, a prelude. That means that it is like an introduction to something more significant.
The piece opens with a series of chords that have a rhythm like a funeral march, which is emphasised by the fact that the key here is F# minor, creating a solemn atmosphere. In bar 17 however, the meter changes to 3/4, and introduces the fugal subject (in C# major) in the piano left hand. This sequences, moving the part upwards. This exposition of the subject is then answered in the piano right hand, and in bar 33 is presented again by the soprano voice. Bar 41 marks the beginning of the episode with ascending scale patterns; the left hand imitating the right hand. This passage is then transposed up a 4th.   In bar 47 there is a motif in the piano part that seems to mimic the exposition section in bar 17. In bar 59, there is an ascending sequence, that is similar to the one in bars 41-46, except that the main part is the soprano voice. In bar 69 we get the beginning of the "re-exposition" and the subject from the bass in bar 17 is played again, transposed down a 5th. This is answered by the soprano part in bar 77. At bar 85, the soprano has a similar sequence to that at bar 41. There are many places where parts are repeated, for example bar 91 is similar to bar 47, bar 101 to bar 57, and bar 103, to bar 59. In bar 119, there is a chromatic passage that descends (although the contour of each bar means that it is not a perfect chromatic descent). There is then harmonic instability until F# minor is re-established in bar 139, because we get the tonic and dominant (139 and 141) played. At bar 141, the right hand is similar to the 'head' of the subject. This continues on until the key becomes F# major (the parallel key) at bar 145. The movements ends with very similar material to that of the beginning, in order to round it off. It ends in F# major.
After the movement, there is a tiny Ritornello that brings the key back to C major, for the Sanctus movement.