The Mystical Power of Music by Avraham Aryeh Trugman (pg.41) - "Music, perhaps more than any other medium, has the unique ability to express and mirror the full range of human emotions, consciousness, and experience. Its appeal on one hand is universal, transcending race, religion, culture, and era, while on the other hand nothing captures the particular essence of a specific culture, religion, era or individual better than music. It allowed the soul to soar to heavenly heights, giving wing to man's most glorious aspirations and dreams. It expresses as well man's greatest pain, sadness, and existential loneliness.
(א) הַֽלְלוּ־יָ֡הּ הַלְלִ֥י נַ֝פְשִׁ֗י אֶת־ה' (ב) אֲהַלְלָ֣ה ה' בְּחַיָּ֑י אֲזַמְּרָ֖ה לֵֽאלֹקַ֣י בְּעוֹדִֽי׃
(1) Hallelujah. Praise the LORD, O my soul! (2) I will praise the LORD all my life, sing hymns to my God while I exist.
רבי עקיבא אומר: זמר בכל יום זמר בכל יום אמר רב יצחק בר אבודימי מאי קרא שנאמר (משלי טז, כו) נפש עמל עמלה לו כי אכף עליו פיהו הוא עמל במקום זה ותורתו עומלת לו במקום אחר.
Rabbi Akiva says: Sing every day, sing every day, i.e., review your studies like a song that one sings over and over. Rav Yitzḥak bar Avudimi says: From what verse is this derived? It is as it is stated: “The hunger of the laborer labors for him; for his mouth presses upon him” (Proverbs 16:26), i.e., he exhausts his mouth through constant review and study. He labors in Torah in this place, this world, and his Torah labors for him in another place, the World-to-Come.
Sing every day - Even if one has reviewed his learning, he should sing it every day, and this will cause your life in the World to Come to be with happiness and songs.
And Rabbi Shefatya said that Rabbi Yoḥanan said: Concerning anyone who reads from the Torah without a melody or studies the Mishna without a song, the verse states: “So too I gave them statutes that were not good, and judgments whereby they should not live” (Ezekiel 20:25), as one who studies Torah through song demonstrates that he is fond of his learning. Furthermore, the tune helps him remember what he has learned.
The Mystical Power of Music by Avraham Aryeh Trugman (pg.41) - "The word for "song" in Hebrew is shirah, equaling 515, the same as the word for prayer, tefillah. This is not a mere casual connection, but rather a fundamental lesson on the essence of prayer and song.