20th Century Hit Song is a music program; this particular episode seems to be a ranking of old hit songs that contain surprises. The surprise they talked about here is that BYMW was written & composed by Psy. But they also talked about other things (like SeungGi being voted #1 singer whose comeback is urgently needed) and showed some rare footage (like SeungGi singing BYMW as a duet with Teacher SunHee).
credit: KBSNCHannel
thanks a lot for this update looking forward to the next