The words Binary and Ternary simply mean two and three and refers to music which is in two or three distinct sections. If you hum the tune to Twinkle, twinkle little star in your head (this is called internalising the music) you should be able to distinguish the three sections. If we were to give each section a letter, it would look like this:
twinkle little star, how I wonder what you are.
B Up above the world so high, like a diamond in the sky.
A Twinkle, twinkle little star, how I wonder what you are.
So music in ternary form is can also be called ABA form, whereas binary form is simply AB! Look at the following two pieces of music and mark which form the music is in:
Using binary and ternary form is a good way of extending your compositions and giving them a good shape. Compose a rhythmic melody which is in ternary form and uses sequence in one of the sections. Don't forget to include expression, dynamic and tempo markings in your composition. Make sure that you play the music to your classmates and ask them if they can identify all of the elements you have included.
(N.B. Click here for the answers)