Kobo makes an eight inch e-reader for $270. That's about two inches larger than even a fairly large e-ink reader. It has hardware page turn buttons, I think, but the screen can also be tapped.
Or the Boox Note 3c, which has a 10" screen (don't go for the color screen, the contrast ratio is much worse), also has a front light, $400: https://shop.boox.com/products/noteair3 with the added advantage of running Android 12, so you can install a sheetmusic specific app.
Or there's this $400 transflexive display android tablet, B&W only (not even grayscale) and no backlight:
Or the Boox Note 3c, which has a 10" screen (don't go for the color screen, the contrast ratio is much worse), also has a front light, $400: https://shop.boox.com/products/noteair3 with the added advantage of running Android 12, so you can install a sheetmusic specific app.
Or there's this $400 transflexive display android tablet, B&W only (not even grayscale) and no backlight:
https://goodereader.com/blog/reviews/unboxing-the-hisense-q5...