Four Images after Yeats was written in 1969 and first performed by Ronald Lumsden in Southampton the same year. The first three movements of this work reflect briefly on fragments from Yeats' poems, but the last introduces musical quotations as stimuli to my arguments.

In each of these pieces I wish to direct the mind of the listener towards something outside music as an extra dimension of meaning to the purely musical levels. But this does not mean that it is any more important than them, it is something extra, which intertwined with my musical thoughts during composition.

Above the first there is the following quotation:

A tree there is that from its topmost bough
Is half all glittering flame and half all green
Abounding foliage moistened with the dew.

With Yeats' marvellous and complex tree symbolism one associates bird images, especially the artificial ones: "Miracle, bird or golden handiwork… planted on the star-lit golden bough", and I have interwoven one with the branches of this tree. A quiet melody based on falling sevenths is heard beneath a delicate invocation of the imagery of the poem.

The second piece is a tiny representation of Yeats' moon symbolism. It faithfully mirrors the twenty-eight phase palindromic waxing and waning, and the score has several quotations from The Phases of the Moon scattered over it. The moon's phases symbolise a cyclical view of history - the shape of the piece returns the way it came. In general, there is a progression towards Nature at the full ("the subjective man"), followed by a progression towards God ("the objective man").

The third concerns itself with Yeats' fascination with the mystical meaning of numerical symmetry. He thought the imaginations of lovers capable, in their most inspired and frenzied moments, of visualising something of the perfection of the soul after death, a perfect (and therefore symmetrical) beauty of ultimate sexual desirability. This short quiet movement uses the sevenths of the opening, and its peaceful beat calms us, to prepare for the turbulence of purgatory.

After the three short pieces comes a long complex movement. It is entitled 'Purgatory' and was suggested by aspects of Yeats' theory about life after death. It makes extensive quotations from music of the past - Bach, Mozart, Schumann, Liszt, Scriabin and Schoenberg - churned round in an ever-faster roundabout. Each quotation feeds the musical argument with new data until the turbulence is stilled.

In the Return, the Spirit must live through past events in the order of their occurrence, because it is compelled by the Celestial Body to trace every passionate event to its cause until all are related and understood, turned into knowledge, made a part of itself. All that keeps the Spirit from its freedom may be compared to a knot that has to be untied or to an oscillation or a violence that must end in a return to equilibrium. A Vision