After the red sea covered the enemies of Israel, we read: Then Moses and the children of Israel sang this song to the Lord, and they spoke, saying, I will sing to the Lord, for very exalted is He; ( Exodus 15:1) The Song at the Sea is one of the great epiphanies of the Jewish experience and of human history. According to the Mechilta, "what a maidservant saw by the sea, Yechezkel Ben Buzi (the prophet Ezekiel) did not see in all his days.". As a result of what they saw they broke into collective prophetic singing. In tractate Sotah there is a discussion amongst the sages as to how that manifested itself. Did Moshe receive the vision and then teach the song to the others or not? "Rabbi Nehemiah said: It was like a schoolteacher who recites the Shema in the synagogue. He begins first and they continue after him." (Sotah 30b) Rashi explains Rabbi Nehemiah's view as saying that all the people were seized by divine inspiration and the same song and words came into their mouths at the same time. Yet we read the following Midrash in the tractate Megilla; When the children of Israel crossed the red sea the angels wanted to say Shira ( songs of praise ). Hashem said to them, "Ma-asai Ya-dai Tavu Ba-YAm Ve-Atem Omrim Shirah ?",( my creations are drowning in the sea and you want to sing Shira?) (Megila 10b) . HaShem is telling His angels that this is not the opportune moment to be singing, even if those that have perished may have deserved their punishment Why is one singing considered meritorious and the other is seen as inappropriate? Angels are creatures without free choice. To better understand angels, it is better to see them as “the message” rather than as “the messenger”. They simply bear the word and purpose of G.d. The angels were simply responding instinctively to the destruction of evil. Their song would focus on the end of evil and on the beginning of the redemption. Yet their response did not come of what they themselves experienced .That experience was external to them. The midrash then was teaching the lesson we read in a verse from Proverbs : “When your enemy falls, be not glad, and when he stumbles let your heart be not joyous. Lest G.d see it and it displease Him, and He will turn His wrath from Him unto you” (Proverbs3:5) Yet when the children of Israel experienced their own redemption and physical salvation their souls burst into song."HaShem is my strength and song, and He is become my salvation , this is my G.d, and I will glorify Him; my father's G.d, and I will exalt Him." Shira stands out as being one of the most spontaneous and prophetic of the ten forms of Praise ( described in tractate Pesachim 117a). "Shira" is unconditional praise. The Midrash Tanchuma (on Beshalach 10.) describes ten examples of “Shira” in the history of Israel.All of these were examples of the souls simply bursting into song. Spontaneous expressions formed out of a deep mixture of deep yearning and thankfulness The first of these examples of “ Shira “is the song sung on the night of the Exodus in Egypt,(Isaiah 30:29.). The second is Shirat Hayam ,the “Song at the Sea,”(Exodus 15:1-21.) . Then there is the “Song at the Well,”(Numbers 21:17-20.). The fourth is the song of Moshe at the end of his life (Deuteronomy 31-32.) . Then the song of Joshua when he asked HaShem to stop the sun,” ‘Sun, stand thou still upon Gibeon; and thou, Moon, in the valley of Ayalon.' (Joshua 10:12-13). Also the song of Devorah’(Judges 5) and King David’s song of praise after his salvation from the hands of his pursuer;(2 Samuel 22)are "Shira". Another was sung during the dedication of the Holy Temple,(psalm 30 ) and the ninth example is King Solomon’s “Song of Songs” The tenth song, says the Midrash, will be the shir chadash, the “new song” of the ultimate redemption; (Psalm 96) In all these cases the songs are songs that came pouring forth after great redemption and release. They come out of souls that understood how close they could have come to oblivion or barren wilderness. They come out of real appreciation of the hand of G-d. as a result they were songs of yearning to be connected to the divine ,songs that glorify the Creator In the final days of redemption all of mankind will truly understand how close they were to oblivion and failure and it is then that they will sing a new song. That song will be unconditional praise as well. The words that introduce the song at the sea “Az Yashir” are written in the future tense. Our sages suggest that the Torah is not only relating to the song of that time, but it is also speaking of the End of days . That is to say that Moshe and his people will sing again just as they did at the Red sea. In fact so will the whole world “Sing to HaShem a new song, sing to HaShem, all the earth ( Psalm 96:1)