Someone recently asked about jam tracks, here is a link to some free ones from Seydel, for a yearly contest they are planning to have till 2016, if I read the page right. I didn't spot it, but I'm sure they restrict use to personal, and no using the tracks for money making recordings. Of course, you could see my signature line in regards to that statement..
http://www.seydel1847.de/epages/Seydel.sf/en_GB/?ObjectID=154492&Locale=en_G B
Bruce K Ritter