"The Deep End" is approximately two minutes and fourteen seconds long in Kingdom Hearts and the HD remake of Kingdom Hearts Final Mix. The piece has a time signature of 4/4, and a tempo of 160 beats per minute.
In Kingdom Hearts, the instrumentation includes: a complete strings section- violin, viola, cello, and stringed bass, flute, trumpet, trombone, tuba, crash cymbals, snare drum, bass drum, timpani, and piano. In Kingdom Hearts HD 1.5 ReMIX, the instrumentation includes that of the original Kingdom Hearts, but also adds: clarinet, and harp.
The thick texture of the piece fits its use as a greater boss theme. The underlying percussion and low brass parts lay the initial foundation of intensity. Over this is a changing interplay between trumpet, flute, treble voicing of the piano, and upper strings. This constant revolving of themes only heightens the tension of the piece.
