I have a kindle and sent a copy of the pdf of my songbook to it. While you can adjust the font size on kindle books, you cannot on your documents that you send to it, which makes them rather small for my aged eyes. It does not move around either the pages or the document very well, unless you set up a lot of bookmarks in the document. So I am still carrying around my 350 page book, which I get printed by a print on demand place (lulu.com) in spiral every six or either months as an improved edition. I also have the feeling that having the songs on an electronic device would be even less welcome than a printed book. Maybe I am paranoid.