The 2003 annotations are from when I first got a computer, discovered .mp3 format and a file-sharing program called Limewire, and set out to see if I could illegally download all the songs, just for the hell of it. The numbers on the left would be the number of seeders I guess, and indicate roughly the modern popularity of these oldies. I made a target list of, by coincidence, all 66 songs occurring across all the sheets I had. I burned a CD of them for a mate, then my computer died and fried the hard drive. My mate claimed he couldn't find the CD, so I lost the lot. It is a credit to YouTube that I had no trouble finding all these.