Italian composer Luciano Berio composed O King in two versions: a chamber version for voice, flute, clarinet, violin, cello, and piano and a symphonic version for eight amplified voices and full orchestra, the latter being incorporated into Berio's Sinfonia (1968) as the second movement. O King is a threnody for the civil rights leader who was assassinated while Berio was teaching at the Juilliard School in New York. A work harmonically based on two whole-tone scales, the vocalist or vocalists of O King "discover" the name "Martin Luther King" first through its vowels then adding consonants until the whole name is sung completely only in the final bars of the piece. A mysterious and mournful piece in which the voice blends uncannily with the instruments and the texture is essentially a veil of slow, shimmering sounds, O King is one of Berio's most immediately appealing and affecting works.

© James Leonard, All Music Guide