It looks like there is free and legal music out there, though it is rather limited in scope on this site for the types of music I am interested in. There were 111,052 free MP3s here on music.download today: that's quite a few since January 16 when Jennifer posted that there were 110,462. The Thing #48 instructions warned that it was mainly top 40 stuff, but, ever perverse, I hunted around through some other categories like Folk which has 2790 items.
I had been to a Peggy Seeger concert during the week and hunted unsuccessfully for her, not minding as I know there are some songs on her MySpace profile. There were quite a few subheadings in Folk but a lot of them with rather sparse entries. This was also the case for World music where I got excited by the headings Dimotiko and Nissiotiko only to find them empty.
I uploaded an MP3 of an early mediaeval Georgian Alleluia which will be topical next week. The file was easy to upload to my PC and then to play. Use for the library? Well, I can't see much use for my avowed aim of usefulness for local and family history, but the site could be used to provide music for a slide show or video clip. And it would also be useful generally in case library users ask for such a site.