In the Commentary for The Complete Poetry and Prose of William Blake, Harold Bloom tells us that the volume can be 'viewed as a workshop of Blake's developing imaginative ambitions.' Bloom recognizes that these early works of the poet 'give definite form to the strong workings of imagination.' The pursuit of engraving and painting represented one thrust of Blake's lifelong ambition of giving form to imagination; Poetical Sketches demonstrates that the second thrust of communicating through poetry was well developed at an early age.
British Museum Europe Copy D, Plate 11
Poetical Sketches, (E 413) "SONG. Love and harmony combine, And around our souls intwine, While thy branches mix with mine, And our roots together join. Joys upon our branches sit, Chirping loud, and singing sweet; Like gentle streams beneath our feet Innocence and virtue meet. Thou the golden fruit dost bear, I am clad in flowers fair; Thy sweet boughs perfume the air, And the turtle buildeth there. There she sits and feeds her young, Sweet I hear her mournful song; And thy lovely leaves among, There is love: I hear his tongue. There his charming nest doth lay, There he sleeps the night away; There he sports along the day, And doth among our branches play."
Much that is developed in Blake's later poetry is present in these joyful verses. We are challenged to see that disparate items are not separable but 'combine' and 'intwine'. The state of innocence is portrayed in which the imagination is free to play because love and harmony reign.
Perhaps Blake had already formulated the desire that his poetry and illuminations would combine and intertwine as his imagination gained expression in multiple forms which harmonized.