The late Paul Ramsier wrote a book of solo pieces for young bass players. Most have separate accompaniments that can be played on piano or bass. One of the pieces has major thirds all over the place. It's great to play the two different accompaniments and show how the intonation has to be adjusted. Luckily for me, the piano parts are simple enough that even a piano student from a half century ago can play them.As a player of both fretless and fretted bass guitar, playing with equal tempered instruments, I've become annoyingly aware of clashes - my fretted bass, even when tuned accurately (with an equal-tempered electronic tuner) can have a few notes that just don't sound as sweet as my fretless can (when I manage to play it accurately).
Major thirds are the worst offenders - an equal tempered major third is almost 14 cents sharp of a 5/4 ratio major third. If I'm playing an open D string and F# at the 11th fret of the G string, I've learned I need to "push" the fretted string towards the bridge to flatten it. My tuner says that equal-tempered F# is exactly right, but my ear disagrees.
I've been following the discussion in this thread with interest. I've developed an ear for what sounds right - some of the comments here help me understand why it sounds right.
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