The aim of 'Analysing Harmony' is to make some kind of sense or order from tonal harmony as used in the popular music of the mid-20th century; the kind of music that is known as the 'great American songbook' and used as 'standards' by jazz musicians. The benefit of using this kind of repertoire is that, because it is highly 'refined', in the sense of being systematised and predictable, other musics, such as classical and pop, may be usefully compared with it to highlight similarities and differences of tonal use. The particular purpose of the booklet is twofold. Firstly, it may assist songwriters suffering from the 'lost chord' of songwriter's block. The patterns and substitute chords analysed here can provide a range of chords that have the 'correct' harmonic function: it's then a matter of choosing one according to taste. Secondly, an analytical understanding can greatly assist the improvising musician to develop broader and more complex melodic ideas over longer time-frames, rather than responding to each individual chord as it comes along.