Music is prohibited in Islam. The only permissible instrument is the 'Daf' (flat and round- similar to a drum, but with only one side). 'Daf' is akin to the 'Dafli' in India. The version used here has the twin metallic circular dics at the sides, adding a tingling sound to the heavy sound of the instrument. The version used in Gulf is flatter and bigger and mostly without the metallic dics. Though music is prohibited, beautiful recitation of Quran is part of Islamic culture. It is called the 'Qiraat'. When you hear a 'Qiraat' of some Hafiz (one who knows the entire Quran by heart)- the octaves, balancing of low and high pitch and controlling of breath, the best of best singers appear nothing. It is that amazing ! And when a Qiraat or Nasheed (religious song) is accompanied by a beautiful voice, then the entire effect is breath-taking ! And no music (not even a Daf) is required as the words flow with such musical perfection.... Subhanallah!
If on one hand, 'Qiraat' (beautiful and rhythmic recitation of Quran) is highlighted, then why is Music banned by itself? Now there is a philosophy to it...
The main purpose of prohibiting music is the effect it has. You go into another make-believe world, oblivious to the surroundings around you. You might forget your duties and are likely to even forget to remember God. Similar to the effect an intoxicating thing has on a person! Haven't we seen people with plugs into their ears all the time? Such people play their music so loud and get so lost, they cannot hear or see anything sometimes. Some meet with accidents, especially in a crowded city like Mumbai where you hang and travel, cross railway lines to save time etc. We even see some extra smart dudes driving with blaring music and going 'high' on it, singing along alongwith bullying others or knocking someone down, just like the effect 'drinking and driving' has!
Another answer lies in the point -Music is more attached to earthly ups and down! The purpose in Islam is not to get too attached to worldly life as this is just a transitory place. We should strive towards betterment of our afterlife. And Islam doesn't believe in rebirth. You are born, you die and will be brought back to life on the Day of Judgement, when you will atone for your actions. And based on that, your afterlife will be decided. Actually our afterlives start immediately after we die wherein we start paying for our actions from our graves itself.
Yes, a simple song of life and good values and religion can do no harm and is acceptable. But without excessive music. What I want to highlight is that with a good sound and 'sur' and tone and right octaves, music is not even essential. I've heard such kind of 'nasheeds'. But then Music should be basic and not too loud to take you into too much materialism. There are several schools of thought within Islam on this subject. You will find a lot of Islamic music on one hand, while some others totally prohibit.
In my opinion (and what a Muslim scholar would agree with) -A well educated person or an intelligent person knows the difference between moderation and excess. But for the common man, who does not know, for him/her if an excess or loud or large doses of something can destroy, then better to prohibit the smaller dose. Because he/she would not know the defining line between moderation and excess. That is a deeper philosophy.Hence the key to everything is ' seeking knowledge' and learning, which is highlighted in many places in Quran, irrespective of Gender. Hence, in the first Chapter of Quran itself ((Surah Al-Baqarah (The Cow) )) , lot of stress is laid on education and it prohibits people from wishfully thinking or propagating religion in their own way! -''And there are among them unlettered people, who know not the Book, but they trust upon false desires and they but guess.'' (Al-Baqarah 2:78)
So may Allah guide us to the Right Path and help us differentiate between good, bad, moderation and excess!