From Halopedia, the Halo wiki
Overture is the first track (Disc 1 Track 1) included in Halo: Reach Original Soundtrack. It is composed of From the Beginning (0:00-0:17), Swift, Strong, Brave (0:17-2:04), Immemorial (2:04-3:21), Remember Reach (3:21-3:51), and The Fall (3:51-4:47).
From the Beginning
From the Beginning (0:17) features vocals and strings playing a rising progression, which echoes the first phrase of the opening Gregorian chant in the Halo Theme. This piece plays when first entering the menu of Halo: Reach.
Swift, Strong, Brave
Swift, Strong, Brave (1:47) opens with a percussion solo from Pounding the Pavement (from Neon Night in Halo 3: ODST Original Soundtrack) before joined by strings and piano playing a grand melody. The melody plays in variations, soon accompanied by vocals. Together they invoke the opening Gregorian chant from the Halo Theme before ending with a drumroll. This piece plays in the menu of Halo: Reach. A percussion-only version plays in the level The Package, when NOBLE Team defends Catherine Halsey’s lab from the second wave of Covenant, and in Halo: Reach Firefight, during the final wave of a round.
Immemorial (1:17) is strings-only version of Kat’s Plan (from the later track Long Night of Solace), which has incorporated the first phrase from Halo Theme into its suspenseful melody. This piece plays in the menu of Halo: Reach.
Remember Reach (0:30) features brass playing a solemn melody. This piece plays in the menu of Halo: Reach.
The Fall (0:56) is a strings-only version of second section melody from the later track Ashes. This piece plays in the menu of Halo: Reach.
- The name From the Beginning derives from the tagline, “From the beginning, you know the end.”
- The name Swift, Strong, Brave is likely a reference to the Halo 3 campaign level Arrival, when Cortana is describing Spartan-IIs and John-117: "Like the others, you were strong, and swift, and brave; a natural leader..."
- Like Remembrance from Halo 2: Original Soundtrack, Immemorial is approximately 1 minute and 17 seconds long, a reference to John-117.
- The Fall alludes to the Fall of Reach.