John Muehleisen braids two strands in his new oratorio Pietà, to be premiered Wednesday by Choral Arts. The traditional Biblical narrative of Jesus' death and Mary's lamentation, and other liturgical texts, are intercut with scenes from World War I by "war poet" Wilfred Owen and soldier Jack Kipling in letters to his parents, poet Rudyard and his wife Carrie. Seattle composer Muehleisen also finds room in his evening-length meditation on loss for words by William Blake; Martin Luther King Jr.; a traditional Civil War song; the Rev. Anne E. Kitch, who delivered the Homily at Matthew Shepard's memorial service; and the multitalented Robert Bode, this performance's conductor. Adapted Bach chorales serve as interludes in the music, scored for three choirs, soprano and tenor soloists, two oboes, and a varied percussion collection. Though no overt parallels are drawn to current wars, the composer does include a timelessly biting couplet by Rudyard Kipling, especially apropos in a election season that's seeing pathologically irresponsible drum-beating used as political Viagra to pump up doomed campaigns: "If any question why we died/Tell them, because our fathers lied."