Why can't you just give the bassist a handwritten chord chart? Any bassist who's worth anything knows how to play the roots on a given chord chart. (Bassists have to know the notes on their frets, even if guitarists don't

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The problem - I guess - would be if there's specific rhythms or timings; but then tab can't show that anyway!
What I do for bass players who can't read notation (and even for some who can), is give them chord charts with bar lines marked, so they know how many beats each chord lasts for. That's crucial information. And using tab software for that is a sledgehammer to crack a nut.
(Assuming you don't read notation, just count the beats each chord lasts for. Assuming it's in 4/4, divide the number of beats by 4. Mark barlines where each count of "1" is. Eg, a 12-bar blues in A would look like this:
Code:
|A |A |A |A |
|D |D |A |A |
|E |D |A |A |
If it's clearer to add beat markers, use additional slashes like this:
|A / / / |A / / / |A / / / |A / / / |
|D / / / |D / / / |A / / / |A / / / |
|E / / / |D / / / |A / / / |A / / / |
That way, if you have faster changes, 2 or more chords per bar, you can mark where they fall.
Even with that level of detail, it's going to be much quicker for you to prepare than using tab software (or handwriting tab).
It would have be a pretty dumb (and rare) bassist who couldn't read that. Or are you saying that the typical bass player you meet doesn't know how to find an A note on their bass?? (If so, I'm not surprised the ones who can are so busy...

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Are you perhaps (reading between your lines) looking for software that will translate
audio information (eg from an MP3) into tab or notation? If so, good luck, but don't hold your breath. I'm sure many brains have been working on that for some time, but AFAIK no success yet. (There's been some limited success with notation, but only from very simple information.)
"The most important rule in music is you must always avoid discord. Use dat chord instead."