Quick Study: Bach Prelude in C
Bach was the man. Few will dispute his genius and the impact he had on music. Back in the day, more specifically the baroque era, Bach wrote a set of pieces for solo piano called
Boom! Just in the first few measures, you see a bevy of chords, most of them in inversion! Each measure is simply an arpeggiated chord spread across the piano, so you'll have to take inventory of the notes that happen in each measure to follow along. Look at a blow-by-blow recap of what you see.
Measure One: C major chord (I), root position. No big surprise here.
Measure Two: D minor chord (ii), third inversion! Not a shocking chord, but the inversion allows the C to stay in the bass from the first measure — very smooth.
Measure Three: G7 chord (V) in first inversion. The first inversion allows a B to take the lowest voice. That's only a half step down from the preceding C in the measure before. Again, look how he's connecting these chords.
Measure Four: C major chord (I), root position. The B from the last measure has come back to C. In four measures, with four chords, the bass note has either stayed the same or moved down only one half step.
Measure Five: A minor chord (vi), first inversion. The C stays in the bass because of the inversion!
Measure Seven: G7 chord (V), first inversion. Our C from the preceding three measures has finally moved, but only down to B, one half step!
Measure Eight: C major seventh chord (I), third inversion. The B from the last measure will stay in the bass because of the third inversion of the C major seventh chord. (Give Bach some props here for using a “jazz” chord 200 years before jazz came into existence!)
That's a good place to stop and take inventory. There are a bunch of different chords: C, C Major seventh, D minor seventh, D7th, G7th, and A minor. In eight measures, you went through six different chords, most, if not all, of which were in inversions. What's the result? The result is an abundance of musically interesting chords that move so smoothly from one to another that it almost sounds as if they're molten lava flowing from voice to voice. In those eight measures, our bass note started at C and never went below B! That's only a half step down! Amazing!
You owe it to yourself to check out the rest of the piece. The book stops here because things start to get theoretically complex and Bach introduces chords and concepts you haven't learned yet. By the end of this book, though, you should be able to analyze the rest of the piece with ease. And it's worth looking at — many theorists rely on this piece as a perfect example of common practice harmony in action.
Next up: You get to learn how chords progress from one to another — chord progressions!