To legally distribute a cover song, you must obtain the proper license and pay the copyright owner of the song you are covering. This even applies to when you want to release the song for free on services like YouTube and Soundcloud. If you don't, you risk getting sued by the copyright holder for distributing their copyrighted work without the proper license!
Here are certain steps you should follow to protect yourself from litigation:
RELEASING COVERS FOR FREE
When you plan on releasing covers for free (for example, on Soundcloud) you still need to get permission and/or obtain a license from the original songwriter(s) so they can get properly compensated for the use of their work. Services like SoundCloud often require you to provide proof that you do have permission from the relevant rights holders or can provide the relevant licenses to release the cover.
If you need to apply for a license, you will have to provide an estimate of how many downloads you expect as well as how many streaming services you plan to distribute the song to (keep in mind that because streaming services like Apple and Spotify already pay licensing fees you don't need to include them in your list of DSP services, you would want to include services like SoundCloud, Bandzoogle, Bandcamp and any similar music platform).
INCLUDING A COVER SONG ON YOUR OWN ALBUM
If you plan on releasing a cover song on your next album, you will need a mechanical license. Currently the statutory rate for mechanical licenses is 9.1 cents to the songwriter per a download or physical purchase of the album. To get this license you have a few options, including going through Harry Fox Agency's Songfile, sites like Easy song Licensing, or by contacting the copyright holder directly. For example, if you want to cover a work Songtrust currently administers, you can email us directly to obtain a mechanical license instead of going through a 3rd party service like the Harry Fox Agency. In addition to this, most distributers (such as CD Baby) will also help you obtain the proper licenses to release a cover song.
Keep in mind that if you want to release two different versions of the cover song (ex. a live version and studio cut) you will need to obtain two separate mechanical licenses.
PLAYING A COVER ON YOUTUBE
Because YouTube is a video platform, you technically are required to get a synchronization license to legally upload a cover. But this is unrealistic for independent musicians, so instead YouTube just displays ads on cover videos and pays the revenue to the copyright holder. So, if you just plan on releasing a cover on YouTube and nowhere else, you do not need to obtain a mechanical license. YouTube will simply will pay royalties to the publisher from revenue generated from the ads displayed on your videos. You can learn more about monetizing content on YouTube here.
Lastly, please note that you cannot register a cover song into your Songtrust account regardless if you obtain the proper licenses or are granted permission to distribute it by the copyright owner. This is because a cover is not considered a new, original piece of music - you do not own the copyright for this work, thus cannot collect any royalties generated from the underlying composition.