A ground bass is a bass line that never stops repeating in a piece of music. They are everywhere and are much more common than you might think. Pachelbel’s Canon and With or Without You by U2 are a couple of famous examples, but there are millions to chose from. Some of the oldest music that we have is built from ground basses and I keep hearing them in new popular songs and film music.
They also are the easiest music to improvise and provide a great way in for people who are new to improvising. When we learn piano it’s really important to learn to read music, but it’s also important to learn to play by ear and to create your own music when you are playing the piano. The instructions below might be too complicated for a beginner, but with just a few piano lessons you should be able to do this.
Let's start with a really simple ground bass. In the left hand slowly play a 4 note descending scale starting on A. The notes will be A G F E. Play them really slowly over and over again. This is an ancient ground bass called passamezzo antico, but that is not important. Its still being used to create awesome music today.
Now with your right hand start to add notes over the bass line. You could move down in parallel thirds. C B A G#, or something really different like E E D E; you could even do both at once! Try adding chords. You could try A Minor, E Minor, F Major, E Major with each of the bass notes in order. Keep playing it over and over and slowly change things and see how many different patterns and moods you can create.
Once you have enough patterns you should try creating a piece of music that has a beginning, middle, and end. See if you can make it interesting and varied. Maybe it could start with just the bass line really softly, and slowly add onto it, and end up with a loud climax. Any maybe it could be completely different. This is your piece after all!
Many songs have been written over this bass line. Probably the most famous is Greensleeves or the Christmas Carol What Child is This. Now you have played the bass line and created your own piece over it, maybe you can work out the notes of this famous song and play it by ear.