Hi, I am working on a website and have a few questions regarding copyrights. I am creating a site for parents and their children that pools together resources I have collected as a music educator. I have a song section that contains about 50 of my favorite folksongs with mp3's (my acapella singing).   I have made sure that these songs are in public domain. I wish to add more but these songs are of known authorship. I know that mudcat includes many songs of known authorship and posts the following at the bottom of the page : "PLEASE NOTE: Because of the volunteer nature of The Digital Tradition, it is difficult to ensure proper attribution and copyright information for every song included. Please assume that any song which lists a composer is copyrighted �. You MUST aquire proper license before using these songs for ANY commercial purpose."

So if I am not using them for profit, is okay to post lyrics and an mp3 of my singing?
Here are few more scenarios...

If someone has aurally collected folksongs or rhymes and recorded them in a book, can I reprint that song or rhyme and just cite the book?

What about a classic song like "Somewhere over the rainbow" - do I need to find if the copyright has been renewed?

Can I include a video from youtube of "Singing in the Rain" from the original movie?

There are so many sites such as mudcat that list lyrics- I just want to make sure I am doing the right thing.

thanks! amy