During my A level studies figured bass and four part harmony weren't high on my list of priorities - and I certainly never imagined that I'd choose to attempt an exercise in the small hours of the morning out of choice.

However, not feeling inclined to sleep I find myself enjoying the therapeutic feeling of a 2B pencil in my hand (always use a soft pencil as rubbing out is inevitable) as I carefully work through Soprano, Alto, Tenor and Bass lines. There's a calming quality to sketching out of the harmonies and following the rules. For those who might be interested the rules of four part harmony are best remembered by: F O O L S and the two Rs…

F: FIFTHS -Check there are no consecutive 5ths between any combination of the parts
O: OCTAVES -Check there are no consecutive 8ves between any combination of the parts
O: OVERLAPPING -Check that no part overlaps the other in adjacent chords
L: LEADING NOTE -Check that the leading note (7th) always rises to the tonic (8th)
S: SPACING - Check that there isn't more than an eve between any of the parts - except between bass and tenor where this is acceptable
R: RIGHT NOTES - Check that all notes of the chord are appropriately used. Don't double the 3rd except in a minor chord
R: RANGE - Check that each 'voice' is within its appropriate range, not too high or too low

When I was eighteen I thought that this was an impossible exercise and just couldn't see how it was to be managed. Perhaps I'm a late developer - although I wouldn't say it's ever a really easy task. However, is readily achievable with a little careful thought…

- and now I'm choosing to do this as a method of relaxation until sleepiness creeps upon me. I always think better with a pen in my hand - and a pencil is so much more tactile. The scratching sound of pencil on paper is all part of the pleasure. I'm adding extra annotations for the benefit of some of my advanced theory pupils, so that they can see what to look out for and what processes to follow.

There are all sorts of quiet things I could be doing. I could be sorting the washing out or I could read a book, but tonight I'm in the mood for Bach Chorale type harmonisation. The 'un-rushable' process of harmonising each crotchet beat is gradually settling my mind. I'll do a last check through and then I'll attempt sleep - again!