You might have run across this column, formerly titled �Stranger In Town,� in New York Rocker, where it appeared for six years, took a year off when the magazine did, and returned for two ephemeral issues early this year. If you�re in the large majority which hasn�t seen it, a brief explanation is in order. As the new title suggests, this is a column about singles, which I consider tbe essential medium for the compressed impact of the best pop and rock �n� roll—that single song, heard on the radio or in a record store or at home, that stops you in your tracks, sends shivers down your backbone, and reminds you once again of the sheer power music can have.