The music industry has kept track of what people use as their signal source in their music systems. The animated gif shows each year from 1973 to 2012 (40 years).
I found that you can STOP the gif's animation on any one year by hitting F10 on the keyboard (at least this works on my PC with Windows 7) If I hit F10 again it will start up again but it seems to skip a year? If you know how to start and stop the gif and not skip a year, let me know ?
Bob