Actually Diki the reason Yamaha music is so big and Brand loyalty is so great, is because of the Yamaha music education system.
If you remember in the 70s Yamaha were a joke in the music industry both here (Europe) and in the US, however when they introduced their music schools, parents started buying Yamaha’s to match what their kids were learning on in the schools, then of course they moved onto the parents, showing them that they as well as their kids could learn to play, which meant even bigger model sales.
All this culminated in the 80s when the sales of Yamaha instruments was such that most of the competition from Europe and the US was wiped out, leaving only the really big companies, (Like Lowery) and small premium niche market manufactures (Like Wersi) still in business.
Only Technics offered any real competition. (And that was because they introduced the Technics Music Academy)
The tactic was not new, as Yamaha had already done this successfully in the Asian markets.
Whether you like Yamaha or not, their marketing, sales and brand loyalty is unmatched by any other, no matter where in the world you go.

Bill