Originally Posted by: dougjtIt's called a tie, you just hold the note but don't pick it again
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|----5-(5)----5------------|----5-(5)---5-----------|
|-6----------------6-(6)---|-6--------------6-(6)---|
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A tie is usually a bow over or under two notes. I am pretty sure he is talking about a ghost note, which is an optional note.
I have been corrected I always played them as ties
The best description of a ghost note, is a note that is felt but not heard. You will play the note softer, and without emphasis. A ghost note can be played by fretting a note, but not picking it. Ghost notes are barely audible, but they do a lot to the feel of the music. The notation for the ghost note is round brackets
Here is one of the sources of info I was looking at Songsterr