I’ve now finished working my way through the volume of Mozart piano sonatas (a sonata a day keeps the doctor away) and have started playing through Beethoven’s again.

The early Beethoven sonatas have made me think about what makes the difference between a theme and a melody. A theme, I think, is a series of notes to be used as material throughout the piece. It doesn’t need to be singable to work as a good theme. For example, the first theme of the first Beethoven sonata (a spiky rising arpeggio) is a theme, but not very singable. Beethoven takes it apart and uses it as building material for other themes in the sonata.

I suppose I’m thinking about the difference between an instrumental theme and a melodic theme. Some themes (like the opening of the first Beethoven sonata) make sense to the hand, but not to the voice – not, that is, unless you are the sort of soprano who can sing Mozart’s ‘Queen of the Night’ aria. All the opening themes of the early Beethoven sonatas are instrumentally than than vocally conceived. It’s not a strain for the fingers of the hand to play them, but it would be a strain for most voices to sing them.

A melody is a memorable tune, pleasant to sing. It may only occur once in a piece. It’s not necessarily a source of material for future development.

Some themes are also melodies, of course – both a source of material for the development of the piece and memorable tunes in their own right. That kind of melodic theme is more often found in a slow movement. It often has a largely step-wise movement, often with a leap of some kind at the climax of the melody. The slow movement of Beethoven’s ‘Pathetique’ sonata is a good example.

To make things more complicated, however, a singable melody isn’t always a great melody. For example, the melody of Beethoven’s ‘Ode to Joy’ in the last movement of his Ninth Symphony is eminently singable and easy to memorise. It moves smoothly step-wise and in a simple rhythm. It doesn’t have any surprising or striking leaps.

Is it a great melody, though? Personally, I find many other Beethoven melodies greater – in the sense of more emotionally satisfying. The slow movement of Beethoven’s Archduke Trio, for example, also moves stepwise and in a simple rhythm but covers a greater range and, for me at least, is more involving.