I determined the start time of each tune by watching the elapsed time displayed by a CD player or a music player application on my computer while listening for the start of the tune. This process is inherently error prone, especially when using computer applications where the elapsed time indicators seem to be updated irregularly. If the source material is an LP or cassette, additional timing errors can be introduced during playback due to mechanical variations in the players. It would not be surprising, therefore, if the start times you observe when playing a recording differ by up to several seconds from those displayed in this index. A larger difference might indicate a mistake on my part that should be corrected.