

Ultimate, “Hollow Bastion” is a track used in stages. Other appearances Super Smash Bros Ultimate Featured in Kingdom Hearts Birth by Sleep, it is even slower than "Reviving Hollow Bastion". " Radiant Garden" is a remake of "Hollow Bastion" with a more pronounced brass and louder choral arrangement. " Reviving Hollow Bastion" is a slightly slower and less dark remake of "Hollow Bastion" featured in Kingdom Hearts II. The last four measures of this section return to the first section's phrasing and progression, allowing for a smooth transition between loops. This section momentarily shifts from the key of B minor to the key of C major. In the fourth section, "D," the previous three sections merge to create a greater impact, in both appearance and sound. This rhythmic difference lasts for four measure before returning to their initial rhythm. This longer note is a drone that continues throughout the section it is known as "B3," or the in-scale second line note of the bass clef. However, unlike in the A section, the lower voices/instruments move from single eighth notes falling on beats 1, & of 2, 4, and 5, to a tied whole and quarter note. In the third section, "C," the dance-like rhythm from the first section reappears. This second sections lasts for a total of four measures. Starting with the oboe solo- pickup notes to measure fifteen, the dance-like rhythm is temporarily broken up with a quarter note rhythm. These chords lack the third scale degree and place the fifth in the melodic line. This section features the strings and bass, in which parallel diatonic seventh chords are used. This occurs around the thirty second mark and is easily felt or perceived by the listener. In the second section, "B," a new, more ominous texture appears. This concludes the first section of the piece- otherwise referred to as "A."

During this section the tenor vocalists join in, continuing the long note drone in the background. Fifteen seconds into the piece, the violins join the harp, increasing the dynamic of the rhythmic phrase. This is very short and fleeting, as around the twelve second mark the harp returns, reclaiming the melodic line. Around eight seconds the piano enters, continuing the dance-like rhythm first featured on the upper voicing of the harp. The piece opens with the soprano choir members singing a drone note in the background. This dancing rhythm is not only the main melody of the piece, but is also what keeps the piece energized and continuously moving. This is heard and supported by the lower harp part, playing a single eighth note on beats: 1, the & of 2, 4, and 5. The grouping of the eighth notes causes the piece to be conducted asymmetrically as the groupings are 3-3-2-2, thus allowing this piece to be conducted in four. This rhythm consists of the double pairing of eighth notes, with a total of five pairs- or ten eighth notes, total. The piece is characterized by a recurring syncopated, dance-like rhythm that is set-up in the beginning seconds of the piece. The instrumentation consists of a complete strings section- violin, viola, cello, and stringed bass, oboe, clarinet, timpani, piano, organ, harp, and chorus. "Hollow Bastion" is written in the key of B minor and has a time signature of 5/4 time. Regardless of the game, the piece is played at the prestissimo tempo of 180 beats per minute. In Kingdom Hearts Re:Chain of Memories, the piece is slightly extended to two minutes and thirty-six seconds. "Hollow Bastion" is approximately two minutes and twenty-six seconds long in Kingdom Hearts and the HD remake of Kingdom Hearts Final Mix.

"Hollow Bastion" is the field theme of Hollow Bastion in Kingdom Hearts, Kingdom Hearts Chain of Memories, and Kingdom Hearts Re:coded.
