Bleeding music

In my post of a few days ago, Steve Hoffman, he mentions on his cheap Henry Mancini CD there's really good 'bleed' that he likes to listen to as a means of evaluating equipment's ability to resolve small details. Several of you caught that reference and asked me to explain what he meant. 'Bleed' refers to 'tape bleed' a ghosting you can hear on some cuts of music. A good example is one I've used often, the Shelby Lynne title track Just a little lovin'. In the middle of the song, the band stops playing, there's a pause and Shelby sings alone just for a moment. If you listen closely when she sings:

'...This old world, wouldn't be half as bad, It wouldn't be half as sad, If each and everybody in it had, yeah'

Half a second before the first line quoted in the lyrics, you can hear a ghost of her singing 'This old world' just before she actually sings it - if your system is resolving of small details. Tape bleed happens when the tape has been around for a while and the layers of tape sit close to each other on the reel. Because tape is a magnetic medium, each layer slightly magnetizes the layers above and below when tightly wound on the reel. If they sit long enough on the reel, this bleed happens to every turn of tape. You only hear the bleed when the musicians stop playing for a brief moment. That's tape bleed.