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Stupid Tab Question #447: What’s the meaning of this diagonal line here?
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I am guessing that would be a slide. In other words, strike the note at the 2nd fret and then slide to the 4th fret for the next note. The tabs Ben uses here will typically have an “sl” over a slide.
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Stupid Tab Question #448: What’s the point of putting that 0 over the 4? Surely I’m not expected to pinch the open D string and the B fretted at 4 here…??
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As you arrive to fret the note at the fourth fret (from question 447), you will simultaneously strike an open note on the highest pitch string. The value of that note will vary depending on the instrument and tuning.
One of the neatest things for helping with tabs is Tabledit software. The reader version is free. With it, you can “play” the tab, and slow it down to hear what is going on. Here is a link that will help with getting started with Tabledit:
https://banjoebenclark.com/forum/t/tabledit-viewer-basics/584/1
FWIW, you can also add an image or tab to a message, but I like that as an avatar. It’s an innovative use of it.