アカペラ

Offrande
for men's choir (or mixed choir)

Oh Christmas Tree
from CoolSide of Yuletide

Oh could we do
Imagination for Chorus with Lyrics by Thomas Moore

Old American Songs I, No. 2 The Dodger (SATB)
No. 2 The Dodger

Old American Songs I, No. 3 Long Time Ago (SATB, a cappella)
No. 3 Long Time Ago

Old American Songs I, No. 3 Long Time Ago (unison choir)
No. 3 Long Time Ago

Old American Songs II, No. 3 The Golden Willow Tree (SATB)
No. 3 The Golden Willow Tree

Old American Songs II, No. 4 At the River (SATB, a cappella)
No. 4 At the River

Old American Songs II, No. 5 Ching-a-Ring-Chaw (SATB, a cappella)
No. 5 Ching-a-Ring-Chaw

Old Fox Wassail

Old Joe Clark
American Folk Song

On Desire

On the Rio

On the Rooms

One day by the river a young Cossack roamed

One Equal Music

One for frost, two for fire

One Hand, One Heart (mixed choir (SATB) a cappella)
from West Side Story

Oolichan

Oratio - Pater noster