Listen to this example of Twinkle, Twinkle Little Star played with a simple accompaniment:
As you listen and follow, notice that the two parts of the music have different rhythms, but the same beat. The melody is simply moving faster than the chords in the left hand.
Now, just listen to the chords and follow the score:
If, instead of playing chords in long notes in the left hand, we break up the chord into its component notes, a different type of texture is produced. Here is Twinkle, Twinkle Little Star again, but now it has faster notes in the bass clef or left hand part, all of which are part of the chord, but played separately instead of simultaneously.
This type of accompaniment is called an Alberti bass. If you have trouble following all the notes, feel the beat and focus on notes that occur with the beat.
Mozart often used this type of texture in his sets of variations and in the Variations On Ah Vous Dirai-je Maman you will find that the second variation uses this principle. This section has really fast notes making up an accompaniment while the right hand is playing the melody. When you listen, you should be able to follow the melody quite easily, so focus most of your attention on the bass clef or left hand part.
Composers often weave several separate lines of music together to create what is known as a contrapuntal texture. Most of us are familiar with songs like Row, Row, Row Your Boat or Frère Jacques that can be sung with one person starting off, and then another and another starting at a fixed interval later. This is called a round or more technically, a canon and it is a type of contrapuntal texture.
If you see a canon written down, you will see how some longer rests work in this type of texture. Here is Frère Jacques written as a round in three parts. Notice the rests before each instrument starts playing and see if you can follow each entry and some of each tune. Play it through a couple of times and see if you can build up from following one line, to following two and then all three together.
Mozart used contrapuntal textures in his sets of Variations, and you will find something very similar to a canon in the 8th Variation on Ah, Vous Dirai-je, Maman. He starts the melody in the treble clef with rests in the bass clef. The bass clef then copies the start of the melody, before moving in a different direction.
Canons are not limited to sets of variations. There is very good example in the slow movement of Mahler’s first symphony that you heard at the end of Week 1 if you are following the FutureLearn course. When you are next listening to music, see if you can spot contrapuntal textures or different types of accompaniment.
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