As the title suggests, H2O is concerned with water, in particular the molecular behavior of three states of water, solid, liquid and gas, thus science is used as a basis to inform the behavior of an orchestra.

H₂O, the chemical formula for water, consists of two hydrogen molecules bonded to one oxygen molecule. Water accounts for around 70% of our planet’s surface, existing naturally in three states, solid (ice), liquid (water) and gas (steam). The water molecules behave differently in each of these states: in ice, they form rigid lattice-type structures affording no movement; instead they vibrate, increasing in intensity as the temperature rises. In water the bonds constantly break and reform, dense and flowing, increasing in energy as the temperature rises until at 100⁰C they break entirely free, expanding outward in a gaseous state. This molecular journey forms the basis for this piece, the orchestra behaving as the water molecules in each state. First: rigid, immense as in monolithic icebergs, unmoving. Second: flowing and dense, and third: floating, ever-expanding.

Of particular interest to the composer is the so-called ‘change of state’ that occurs as ice melts to water, and water vaporises to gas. These link the three main sections creating a continuous movement. As the ice begins to heat, creaking cello and bass effects are heard as the grumbling ice starts to crack. The violas and violins generate trickling sounds along with the glockenspiel, marimba and vibraphone, followed by the wind and brass sections, creating a soundscape of oozing, tumbling water, cascading as the 2^nd section begins. The dense, flowing texture of liquid water can be imagined as the section moves forward with ever more energy as the theoretical temperature rises. The third change of state is then realised with the orchestra portraying the breaking of all bonds, the freeing of the molecules, to fly away, expanding to fill the concert hall.

A new harmonic device was created for this piece and is used extensively in the 2^nd movement, bringing new sounds, portraying the magical quality that is water: that consists of the molecules H₂O.