Playing Playlist With Clean Random Songs?

[mcolonna17]

I have a free account & understand that my playlist can only shuffle.  With that said is there away to stop the random songs that it plays between songs on my playlist?  If that can't not be stopped without paying is there any guarente that the randomly choosen songs will be clean?  I am using spotify in my 7th grade classroom and can't risk inappropriate songs/language be played. 

Thanks for any help/suggestions