Ali & Theo's album O Come O Come Emmanuel is a beautiful and soulful rendition of traditional Christmas carols. The duo's harmonies are stunning, and their arrangements are both inventive and respectful of the original melodies. The album features a mix of classic carols and lesser-known hymns, all of which are given new life through Ali & Theo's thoughtful interpretations. The instrumentation is simple yet effective, with acoustic guitar, piano, and percussion providing a warm and inviting backdrop for the vocals. O Come O Come Emmanuel is a delightful addition to any holiday music collection, and a testament to Ali & Theo's talent and creativity.