An important feature of this arrangement for TTBB a cappella is that the lines given to the accompanying voice-parts are almost as interesting as the melody-line! The accompanying voices even get to sing actual words (as distinct from vocables) in the choruses. In fact, the rhythmic enunciation of text by all the voices is what gives the choruses the stepped-up energy and drive which, in the original version, is created by the addition of the drum-kit. Check out the effect in the audio clip, which is excerpted with permission from a live recording made in 2016 by the Vancouver Men's Chorus under the direction of Willi Zwozdesky.