| It's tricky. I started piano lessons last year late in my life with explicit purpose to learn music theory and apply it to my limited and plateaued guitar skills. It took several weeks to persuade my teacher that "learning music theory" is not the same thing as "learning sheet music". I want to learn truths and relationships and connections which are separate and independent from any specific culturally and historically burdened notation. Notation has its place and I won't claim its useless, of course its not... But i do see too many instructors think it a mandatory step when it isn't (FWIW, I've been studying music theory for a year now with tremendous weekly enlightenment and still cannot read sheet music and it's not my I'm ediate goal. If anything I find that way madness lies - math and relationships and insights of music theory are beautiful and universal and eye opening. Sheet music is a crap ton of inconsistencies we are stuck with, giving privileged view to a random scale and basicly hindering true understanding. I want to build as much understanding as I can before getting stuck in C major as a random baseline :-) So I would say music theory to sheet music is at best math theory to written numbering system. And both are separate from any practical skill that utilizes them - just like you CAN be a great blacksmith or craftsperson with developed intuitive uderstanding of your matter, without learning blueprints and its notation (though it doesn't hurt and for some things it's necessary) |
Music theory without culture and history would have to leave out things like scales, chords, chord progressions, tuning systems (like our 12-tone equal temperament), etc., since they vary between cultures and over time. I'm not entirely sure what's left, maybe the harmonic series?
Sheet music is similar to math notation or written language, and simpler to learn than either of those. It's not the only possible notation, but it's widely used and more compact than say guitar tabs or a MIDI piano roll. If you can't read/write any notation at all you will be limited by how much you can memorize, writing things down is a time-honored tradition for rememering details for yourself as well as for sharing it with others.
So I would suggest that music students learn sheet music plus any other notation that's relevant to their instrument, for the same reason I would suggest that English learners learn to read and write despite English spelling being a crapton of inconsistencies; it gives a lot more options for a modest amount of extra effort.
Can you go through life without being able to read and write, sure. I just don't see why you would want to.