I was listening to Donald Whitney's lecture on Pursuing a Passion for God Through Spiritual Disciplines: Learning from Jonathan Edwards and he read an Edwards quote that has helped me tremendously. This has to be the exact meaning of Ephesians 5:19 ("...singing and making melody with your heart to the Lord...").
"After this my sense of divine things gradually increased, and became more and more lively, and had more of that inward sweetness. The appearance of everything was altered; there seemed to be, as it were, a calm, sweet cast or appearance of divine glory in almost everything. God's excellency, his wisdom, his purity and love, seemed to appear in everything; in the sun, moon, and stars; in the clouds and blue sky; in the grass, flowers, trees; in the water and all nature; which used greatly to fix my mind. I often used to sit and view the moon for a long time; and in the day spent much time in viewing the clouds and sky, to behold the sweet glory of God in these things: in the mean time, singing forth, with a low voice, my contemplations of the Creator and Redeemer. And scarce anything, among all the works of nature, was so sweet to me as thunder and lightning; formerly nothing had been so terrible to me. Before, I used to be uncommonly terrified with thunder, and to be struck with terror when I saw a thunder-storm rising; but now, on the contrary, it rejoiced me. I felt God, if I may so speak, at the first appearance of a thunderstorm; and used to take the opportunity, at such times, to fix myself in order to view the clouds, and see the lightnings play, and hear the majestic and awful voice of God's thunder, which oftentimes was exceedingly entertaining, leading me to sweet contemplations of my great and glorious God. While thus engaged, it always seemed natural for me to sing, or chant forth my meditations; or to speak my thoughts in soliloquies with a singing voice." - Jonathan Edwards
