Studios sell soundtracks to people for 75 dollars. I pay for something that makes soundtracks, it removes the vocals from the song and I am left with the song. Is it halachically permitted for me to make soundtracks for people that ask and sell it for 10 dollars? If not, can I only sell the songs that dont have a soundtrack? Thank you

ב"ה Shalom, I'm not so familiar with this type of technical sale of music. So, I will speak in terms of something which is closer to my understanding. If I understood correctly, your purchase of the soundtrack is like one would once have purchased a cd, but now instead of a cd , you have a soundtrack on some digital medium. The price of 75$ tells me that this is original protected copyrighted material. Therefore, even the vocals are removed from the song because you have the technical know-how, the music remains which is also protected by copyright. And the same would be for the singing without the music which is still intellectual property. The simplest would be to ask permission from the producer, if he minds you selling part of his creation, the songs without soundtrack or soundtrack without sound. This form of sale of music ,which is intellectual property, through soundtracks is not like music on the internet. In regard to downloading music from the internet, on the Hebrew counterpart of this website there are many opinions on this issue. On the Hebrew website, Rav Dov Lior Shlit'a who is the most lenient on this issue says that once a song has been uploaded to the internet, the creator of that music has no control over material that has already been uploaded to the internet and therefore following the laws of "Hashavat Aveida" of returning a lost item, the "finder"- the downloader in this case has no obligation to return it , following the halachic principle of “a lost object swept away by a river". In this case, even if the owner is standing and shouting that he has not despaired of retrieving it , the downloader has no obligation to return it. Even if, in reality, the person would have bought the disc had he not downloaded the songs, it is still permitted to download. However, Rav Lior also wrote that the first person who uploaded the material to the internet certainly committed a prohibition, but it is permitted to download from the internet after that first person has uploaded it. Furthermore, he stated that in cases where the rights-holders are able to demand that websites not publish their songs, there is an obligation to notify the owners that that there songs have been uploaded so they can file a complaint. In your case, you are buying a soundtrack of copyrighted intellectual property, and then you want to sell part of it, either the music or the singing which are both protected. Therefore, without permission from the creators, although you have put in technical work and time in separating the digital components, I do NOT see it as Halachically permitted. If I misunderstood something technical , please correct me and I will again look into the matter. All the best