According to rahyafte (the missionaries and converts website):What are the criteria by which one can distinguish halāl from harām music? Is classical music halāl?
Any music which is lahwī and deviating people from the way of Allah which is suitable for gatherings of merry making is harām whether it is classic or not. To distinguish the subject of a ruling depends on the view of the mukallaf as a part of common people. There is no objection to other kinds of music in itself.
Source: https://www.leader.ir/en/book/32/Practical-Laws-of-Islam
