Other than "I Will Glory in My Redeemer" after Piper's message and "In Christ Alone" (I forget when we sang it), the best musical moment was "How Sweet and Awful Is the Place" by Isaac Watts. The haunting sound of this hymn matches perfectly the lyrics of awe, wonder, and humility. This link will take you to the hymn text, as well as a loop of an organ playing the accompaniment.
There seems to be some disagreement over whether the title should include the word "awful" or "awesome." I can't speak authoritatively to the original, but we sang it as "awful." Knowing how the T4G men view church history, I suspect we were historically accurate.
Next time you pick up your modern hymnal, look and see how much Watts and Wesley you find. If your church uses the MH, compare the quantities of Wesley and Watts to the FG and the RH.