Glover uses a choir singing in a major key to lull the listener. In the FLAC version, you can pan between the left and right channels to hear individual voices—tenors on the left, basses on the right. This spaciousness is the trick; the safer the choir sounds, the more violent the drop becomes.
For archivers, having the original 2018 "upd" (updated/verified studio rip) ensures that this crucial piece of American musical history is preserved in its highest possible fidelity, free from the dynamic range compression imposed by modern streaming algorithms. The Ultimate Listening Setup childish gambino this is america flac 2018 upd