Allah Almighty ordained the reading of Quran with intonation and measured recitation as said in 73:04. (crude interpretation of the meaning)

When asked about the meaning of this verse Prophet Muhammad Peace and Blessings of Allah be Upon Him replied that it means to recite the Quran by manifesting its articulations and pronunciations and not to throw it like the rejected dates….. (crude interpretation of the meaning)

Once Ali Ibn Abi Talib Allah be pleased with him was asked regarding the meaning of Tarteel. He Allah be pleased with him replied

هُوَ تَجْوِيْدُ الْحُرُوْفِ

وَ

مَعْرِفَة الْوُقُوْفِ

Meaning; the beautification of letters(attributional consideration, articulation & intonation) and awareness of the stoppage rules.

Allah Almighty ordained the reading of Quran with intonation and measured recitation as said in 73:04.