The utilization of copyrighted music as an intro in multimedia content, such as videos, is governed by copyright law. The copyright law provides exclusive rights to the owner of the music to control its use, including the right to distribute, perform, and reproduce the music.
In general, it is not permissible to use 20 seconds of copyrighted music as an intro without obtaining the appropriate licenses or obtaining prior permission from the copyright owner. There are some exceptions to this rule, such as the fair use doctrine, which allows for limited use of copyrighted material without permission for purposes such as criticism, commentary, news reporting, teaching, scholarship, or research. However, the fair use doctrine is determined on a case-by-case basis and depends on a number of factors, such as the nature of the use, the purpose of the use, and the amount of the work used.
In order to avoid copyright infringement, it is recommended to obtain a license for the use of copyrighted music or to use music that is in the public domain or licensed under a Creative Commons license, which allows for the use of the music without permission, subject to certain conditions.
In conclusion, while the utilization of 20 seconds of copyrighted music as an intro may not always be in violation of copyright law, it is generally recommended to obtain permission or a license for its use in order to avoid the potential for copyright infringement. As a source, you may consult the copyright laws of your jurisdiction, as well as the specific terms and conditions of the music you are interested in using, to ensure compliance with the law.