For a moment, let’s re-visit that delicious gingerbread house which we looked at in the section about harmony. We had a strong gingerbread structure (harmony) decorated with mouth-watering sweets and icing which make the house look spectacular (melody), but we are forgetting something very important. If you build a good strong house, what is the very first thing you need?
Foundations of course, something to build your house on!
If we tried to build our gingerbread house on nothing, the harmony and the melody would come crashing down. Here is where the bass line comes in. The bass line is the foundation on which the orchestra can then build harmony and melody to give a complete musical structure.
What do we mean by a bass line?
Well, the bass line is the root of the harmony – just as the walls grow out of the floor in a well-built house, so too melody grows out of the bass line.
In the harmony section we talked about keys and said that the most important note in a chord is the bass (also called the tonic) which all the other notes should then agree with to create the perfect harmony. Without the bass line, the rest of the music will not know which notes should be used.
Let’s go back to the opening of Mozart’s Symphony No.40 which we listened to in the section about melody. Here’s a reminder:
What’s important to remember here is that when a group or family of notes sound good together they are in the same ‘key’. Mozart’s music is written in the key of G minor which means that the note G is the root of the key. In other words, G is the home base and even though the music scurries all over the place it always returns to the home base eventually. How does it know where home base is? Well, because it is in the bass line of course!
Here’s the opening of Mozart 40 with the first and second violins on the top two lines playing the melody, the violas providing a lovely harmony on the third line (giving the melody the structure it needs to hold it up), and the cellos and basses on the bottom line are playing a bass line of Gs providing a foundation on which both the harmony and melody are based.