I was reading through some posts on the forum of UK Piano and there was a question from someone about the purpose of learning keys. My own pupils often ask me similar questions. And sometimes when I ask a pupil what key a piece of music is in they’ll reply by saying, for example, “two sharps”. Now what is the advantage of knowing that this music is in D major, (or possibly b minor)? Well learning to think in terms of keys makes learning to play tonal music, or to compose it, much easier. It’s not just that you know what sharps or flats are going to appear in the music but you can also anticipate much of the harmonic structure of the piece. If you pursue Grades 4 and 5 theory you will find yourself dealing with the basic chords around which most tonal music is built. If you are familiar with keys then you immediately know what notes are going to be in those chords and what aural effects those chords are going to have. Playing the piano becomes much easier because your fingers automatically find the chords, and composing music becomes much easier because you immediately know how to achieve certain effects without having to grope around for the sounds you want. If you pursue theory beyond Grade 5 then you’ll be dealing with more sophisticated harmony. Understanding these harmonies is interesting in itself but, again, helps with playing the piano and, again, makes composing music easier, more fulfilling and allows for more adventurous musical gestures. Understanding keys means you’re well on your way to understanding harmony, and understanding harmony is one of the most fulfilling aspects of being a musician. Once you can think in terms of keys – rather than in terms of individual sharps or flats – a whole world of music suddenly becomes much more accessible to you.