Under the direction of guest-conductor Anthony Trecek-King, the Back Bay Chorale brings Handel’s epic oratorio Israel in Egypt to the stage at Sanders Theatre in Cambridge. Handel’s musical retelling of the Israelites’ deliverance from their captors in ancient Egypt is replete with word painting, where the sound of the music imitates the imagery of the text.  Handel’s evocation of the plagues, for example, is particularly effective. Containing more choruses than any other of Handel’s oratorios this epic oratorio is a powerful experience for the music lover.