All three pieces are named after chambers in the Three Counties Cave System. Each one explores a different musical space:
I – Echo Aven – Opening with the piano in its lowest register, the trumpet plays echo-like patterns, gradually slowing each time.
II – Short Long Drop – The piano is now in its highest register, introducing a faster, falling figure, which is gradually taken up by the trumpet. This builds to the piece's loudest section, which vanishes almost as soon as it has arrived.
III – Far Waters – In the longest of the pieces, an extended piano solo covering the whole range of the instrument, leads to the trumpet’s entry. At the end, high, dripping chords in the piano combine with the trumpet’s long, expressive notes.
The trumpet is tuned a quarter-tone lower than the piano. The piece explores the expressive possibilities of the search for consonance, despite the unbreachable differences in their tuning.