With the Symphony No. 4, "Kenosis", completed in 1986, Strutt moved right away from tonality as a source of structural method, and the composition consequently exhibits a high degree of atonality. This one movement symphony, lasting 20 minutes, features a large array of percussion instruments (marimba, bass marimba, vibraphone, xylophone, crotales, tubular bells, Swiss cowbells, tuned gongs, glockenspiel, tamtam, side-drum, suspended cymbol, wood-block, clash cymbols, bass drum, tambourine, wind machine and güiro) set in a normal sized orchestra (triple woodwind, etc.). In fact, 78 players are required in all, including four percussionists. The "Kenosis" subtitle refers to a theological concept which centres on the emptying of the self, such as Jesus Christ is considered to have done.