And what is this emotional awakening of the heart? What is the name of this feeling? What kind of emotion is it? It appears to be the emotion of joy, not just simple joy, but an immense and extraordinary joy – song is the result and the offspring of the greatest joy. An immense and extraordinary outburst of joy, which bursts forth and overflows from the fullness of the heart, is the mother that gives birth to song. And so, we say twice every day in the blessing after the Shema: "Moses and the children of Israel sang a song to You with great joy" – not with simple joy, but 'with great joy,' because the abundance and intensification of joy to the point of bursting forth from the heart is the spring that produces song. Just as it was then, so it is today, that even when we recite the Song of the Sea daily in Pesukei D'Zimra, we are required to say it with joy, as the Mishnah Berurah (Siman 51, Sif-Katan 7) brings from the Zohar: "He should say the Song of the Sea with joy, and imagine in his mind that on that day he crossed the sea, and if he says it with joy, his sins are forgiven." From our words, it is well understood why this is so, because joy is the essence of song, its core, and its foundation.

To show a source that joy is the wellspring of song, the Gemara in Arachin (11a) states: Rabbi Yonatan said, "From where do we know that we do not say a song except over wine? As it is said (Judges 9:13), 'And the vine said to them, Shall I leave my new wine, which cheers God and men?' If it cheers men, how does it cheer God? From here we learn that we do not say a song except over wine." Maran, the head of the Yeshiva, the genius Rabbi Aharon Kotler zt"l (Mishnas Rabbi Aharon on Parashat Beshalach, topic of the song), said that from here we see that song stems from the foundation of joy, and therefore, we do not say a song except over wine, because wine brings joy and thereby prepares the heart for the saying of the song.

Maran, the head of the Yeshiva, also brought the words of the Gemara (there, 10b), that on Rosh Hashanah and Yom Kippur we do not say Hallel because the books of life and death are open, and it is explained in the Rambam (Chapter 3 of Hilchot Chanukah, Halacha 6), that because of the awe of judgment, the joy in them is not complete.