All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad is His slave and Messenger.
According to scholars of Fiqh, the rule is that necessities make what is forbidden lawful. The evidence for this rule is the saying of Allaah (which means): {…while He has explained in detail to you what He has forbidden you, excepting that to which you are compelled.} [Quran 6:119] However, not everything that people consider to be a necessity is actually such. The jurists stipulated an important criterion that prevents personal desires from intervening in the application of this rule. Please refer to fataawa 298732 and 117406.
With regard to the use of an alarm clock that plays music as an alarm tone, then there is no necessity in this because the Muslim is required to take permissible means that would wake him up for the prayer; then, if he wakes up, all the better, and otherwise he is excused. The Prophet said, "There is no negligence in sleep." [Muslim]
Allaah knows best.