Can I upload lyric video of copyrighted songs as a volunteer on YouTube?

Copying someone’s video is copyright infringement and is illegal. Adding lyrics to it doesn’t change the law here. In fact, just posting the lyrics anywhere is also copyright infringement.

You don’t have a right to take someone’s music, take someone’s video, and then distribute it across the internet. And YouTube actively tries to prevent people from using their system to do that distribution. Their Content ID system will detect your music video as a copy and block it, possibly banning your account if you keep trying.

When you press your channel picture on YouTube, you will see a Creator's Studio button.

In the new Window, you'll have a Create button on the lower left (if the language setting is English).

Pressing it will show you an audio library will royalty free music.

And below it you something called Music Policies. In there you have a list of popular songs of various genres, that the copyright owner has agreed for others to use in all\certain countries, while taking the ad revenue from the video you upload.

If you mean a video/ slide show with a song’s lyrics, they are still covered by copyrights. Many musicians license the lyrics separately and, in this sense, you would be damaging their economic interests by destroying the market for their lyrics. Several online services have tried to do this, but licensing is the only legal way to go.

You need to have the owner’s consent first, otherwise they will report it once they find out and it will be taken down.

Yes if you have gained the rights from the copyright owners.

There are always lots of surprises as the federal courts apply copyright law to an unlimited array of creative works, both old and new. Three recent court decisions are reviewed in this blog, (1) a copycat unsuccessfully tried to use the “fair use doctrine” to justify his wholesale electronic copying of the Merriam Webster dictionary, (2) a mother who posted a video on YouTube of her baby dancing to Prince’s Let’s Go Crazy can sue Universal Music for causing a takedown of the video, and (3) the purported copyright holders of the lyrics to “Happy Birthday to You” who had collected millions in license fees are told that there is no evidence that they have any legal rights to the lyrics, thus freeing the lyrics for commercial interests to use without paying.