“Mutations,” “Diapason,” “Open” and “Stopped” are terms I never thought worthy of consideration until now. I’m really enjoying looking into playing the pipe organ more professionally, rather than as a pianist who can just about manage to swing a left foot in the general direction of a bass pedal. Getting both of my feet going on a two octave pedalboard is only one of the challenges it seems, the whole organ registration and technicalities involved in choosing which “stops” to use appears to be a strange mixture of both art and science!

Combinations of voices and pitches aren’t as obvious as it at first seemed. I understand that an 8’ pipe sounds at pitch and so it’s logical that a 16’ pipe sounds an octave lower. Carrying that progression up into the treble - it makes sense that a 4’ pipe sounds an octave higher and a 2’ pipe sounds two octaves higher. Where my maths runs out completely is when ‘mutations’ come into play (if you’ll pardon the pun!) Apparently a 2 2/3’ stop plays at pitch plus a fifth higher, a 1 3/5’ stop produces two octaves and a third higher and a 1 1/3’ creates two octaves and a fifth above pitch. I can’t understand the reasoning behind these numbers and they aren’t easily memorable as it stands....

Voice combinations are where the art mixes into the science and I can only assume that experimenting will eventually lead to a sensitive ear for this sort of thing. Thank goodness many pieces give suggestions for voicing at the head of the music!

In the mean time I’m keeping myself busy trying to get three staves of music to be friends with each other and agree on what beat of the bar it is and I’ve a job on my hands (or my feet, to be more exact) in getting both sets of toes involved in arpeggio exercises.