Sri Chinmoy: Learning a musical instrument is important for those who have musical talent, but not for others. If you have musical talent, then it will help you. But if you don't have a musical ear, then an instrument is absolutely unnecessary. If you don't have the capacity, but want to study because your friends play, or to show off, then there is no necessity in it.
There is only one necessity and that is your daily soulful meditation. If you do that, you will be able to realise God. You may spend your time in music for years and years, but without meditation you will not be able to realise God. If you have a talent, it is advisable to use it. But if you don't have the talent, then don't waste your precious time, which you could be using for a higher, divine purpose. You should just continue with your meditation, which is your inner music.