There is a very simple musical form called ‘ Rondo Form’ which captures the essence of this principle. In France during the Baroque period (1600 – 1750) a type of harpsichord music evolved that used a simple chain like structure. The music would start with an opening theme. Then there would be another separate theme played after it and then the original theme would be played again. This was followed by yet another new theme. Then the original theme would be played, followed by the second theme to have been heard. The piece would then finish with a final restatement of the opening theme. Sometimes the order would be slightly different to this, with the theme played once occurring nearer to the end, but in essence there was always one idea that was introduced in the middle, or sometimes towards the end, that was new and added freshness and interest to the musical form.

This simple, effective form was a favourite not only of Baroque composers but also of the Classical period composers who followed them. If you listen to symphonies by Mozart and Haydn you will often hear a lively, bright and fresh last movement that adds a new musical idea, or a new reworking of a previously heard one, somewhere between its middle and end.

This musical devise was very useful to classical composers, as it enabled them to keep a trick or two up their sleeves for later in their works; keeping their audiences (who were very knowledgeable and aware of the nuances of musical form) interested and attentive. Haydn was especially well known for the musical jokes and surprises he would include in his symphonies, especially during their last movements.