Walaikum Assalam sister! Almost every Hadith which talks against music also speaks against drinking (alcohol), doing zina with girls etc. So these Ahadith criticize that kind of music which can arouse sexual desires and can lead a person to drinking and zina etc. According to those scholars, the music used in Qawali etc doesnt arouse sexual desires, but incites the love of Allah and His Prophet (صلى الله عليه وآله وسلم), so it does not come under the prohibited category. http://www.youtube.com/watch?v=-rCHy5XXz6k