The question is particular to my job situation and requires detailed elaboration of an uncommon problem I am facing. I am an engineer and am responsible to maintain the telephone system of a building so you can hear recorded music when you are put on hold by the operator. An engineer responsible for a telephone system takes care of this music facility as well. This feature is actually against Islamic teachings. What is the ruling of Islam on such jobs which serve genuine needs of people but as compared to the good they serve, a lesser level of wrong is also introduced by them? A caller expects a pleasant engaging tune when he is put on hold to know whether the telephone line has been dropped or not. Moreover, because of privacy concerns, the called party usually doesn't want unnecessary voices to be transmitted when the caller is on hold. Please be kind enough to consider the demonstrated scenario in its true context and advice on the religious value of being a communications engineer.

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The rulings of establishing, maintaining and listening to the musical tone that are in phones or telephone exchange is the same as the ruling of establishing, maintaining and listening to any other sounds of musical instruments. There is no basic difference between them. Therefore, you are not permitted to work to provide musical services or to maintain them. It is very possible to replace this with some Qur'anic recitation or good poetry that is free from vulgarity and music. If doing so is possible then replace it, Allah will reward you; otherwise, look for another job that is free from prohibitions and leave this work. Know whoever gives up something for Allah, surely Allah will give him better than what he had left, and whoever fears Allah, Allah Will make him a way and grant him goodness from ways he could not imagine.
Allah knows best.