What physical scanners do you use to scan your music? I'm having trouble finding one that will scan 9x12 without having to stitch multiple scans together.

Piece of cake. You need a tabloid (11 x 18) or supertabloid (12 x 19) scanner. Many all-in-ones are big enough but you have to think big.

I have an earlier version of this one ($315 on Amazon I think). Best three bills I ever spent. Ink costs lower than a laser printer(!) Full duplex (both sides) print and scan at all sizes. My wife prints 200–300 pages a week and I spend about $78 a year on ink, 1/4–1/5 what my older HP was costing me. Oh yea, it's fast. No so-called "starter" cartridges; these are full sized. We call it Printzilla!

https://www.brother-usa.com/products/mfcj6945dw 

Brother has others that don't support full duplex. XL means it includes more ink in the box — otherwise, it's the same printer.

https://www.brother-usa.com/11x17-ledger-printers#sort=%40productlaunchdatetime%20descending

Epson, Canon and HP also have good units. The PCMag reviews are good for comparison. Unlike the sites that just regurgitate the marketing materials, these are actual tested reviews you can use for product comparison.

https://www.pcmag.com/review/365131/brother-mfc-j6945dw-inkvestment-tank-color-inkjet-all-in-one

That Brother I bought is big and heavy. This AV cart fits perfectly and allows us to wheel it into either of our offices for large scanning jobs. Because of its excellent wireless performance, the only cable is the power cord.

https://www.amazon.com/gp/product/B0039KB7G4/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

I've seen a few tabloid scanner/printers. The reviews on them all range from being "awesome, best product ever" to "this thing was DOA and customer service offered zero help after 4 hours on the phone". That is was led me here to see what people use who would have similar interests in use. I'm not scanning photos and I wouldn't mind printing 11x17 for scores. I will check out the ones you've posted. Thank you!!

You're welcome. Mine is the older, now more expensive, MFCJ6935dw, btw. As far as I can tell the newer one has a bigger screen and the tanks hold more ink but otherwise, they're the same. I bought it when I had a large scanning job and the local copy places wanted over $2 per page for me to self-serve scan. Man, I can buy one for less than that! Yes, I could including that AV cart—so I did.

There are certainly less expensive options, even from Brother, especially if you don't need full duplex scanning and 2 trays + feed. Although large, the footprint can't be much smaller and still have a full tabloid flatbed scanner — many tabloid printers don't and make you stitch images together as you've experienced.

One thing I didn't mention about the Brother. The INKvestment inks are as close to waterproof as anything once dry. To test, I printed black and color sheets, soaked them in water for a half hour and let dry. The paper showed water wrinkling but the ink did not run at all. After uh... less than stellar performance from HP and Epson in that regards, I was blown away.

The downside, if there is one, is that the ink does not saturate the paper like my HP c309a on its Fine setting (or most laser printers). That's ok, I only notice this when I A/B the output between the two. Perfectly great for music, however. 

I can't get rid of the HP, though. Besides being a slightly superior photo printer, it was the last HP that can print directly to CDs (I think it was discontinued 10 years ago). Also, there's no wireless printer than functions as a fax machine—which I still need (the Brother has fax functionality but I'd have to connect it to the phone line). Since Printzilla! I use the HP just enough to keep the heads from getting clogged — everything else goes to the Brother.