Is it necessary to beautify one's voice when reciting the Qur’an, or is Tajweed sufficient? What is the ruling on Tajweed? And is it permissible not to beautify one's voice and only apply Tajweed if that increases humility and contemplation?

Beautifying one's voice with the Quran is commendable. Tajwid is giving the letters their due and their entitlement without affectation. Learning its rules theoretically is a collective obligation (fard kifaya), while applying them practically is an individual obligation (fard ayn). Adhering to the fundamentals of Tajwid is obligatory, though some believe that the only obligation is to pronounce the letters from their correct articulation points, and everything else is commendable. Reading quickly while observing Tajwid (al-hadr) is permissible, but tartil (reciting slowly and distinctly) is the best of ranks. Nevertheless, if quick recitation leads to greater contemplation and humility, then it becomes better, because contemplation is the primary objective. The majority of scholars prefer contemplation and tartil with less recitation over quick recitation with more recitation. The reciter must pronounce the letters from their correct articulation points without substitution. It is commendable for him to beautify his voice without affectation and to recite quickly without violating Tajwid, and contemplation is required of him.