Is it permissible to remove a paper posted on a school wall that is suspected of inviting people to seek musical talents (ma'azif) without permission?

Musical instruments and entertainment tools are Haram by consensus - except for the duff (tambourine) -. Posters that call for their use and encourage mastering them are considered evil acts that must be prohibited and removed if possible, without causing greater harm or corruption, even if the party that placed them did not grant permission.