What recording technology did Glenn Miller use?

"The first authenticated recordings made by Glenn Miller were in 1926. In the fall of 1926, Earl Baker, a cornetist, made recordings on cylinders using the Edison Standard Phonograph recording device, making the first recordings of Glenn Miller, Benny Goodman, and Fud Livingston. Miller and Goodman were both in the Ben Pollack and his Californians band at that time."

https://en.wikipedia.org/wiki/Glenn_Miller_discography

As this was the major recording technique until the mid-1940s (after Miller's disappearance in 1944, it is likely that most, if not all, of his recordings were also phonographic cylinders.

I beg to differ on cylinders. They went out in about 1910. Up to about 1924, most recording was done on wax discs with the sound captured down a dirty great horn, and often two machines used at once to make sure. Rather like the gramophone itself, but with the sound arm controlled to spiral in rather than just following a groove. In about 1924, electrical recording came in, but the discs were still cut in wax by the reverse of a pickup head. Glenn Miller's recordings would have been made by this method. His first recording may have been on a cylinder, but no-one issued cylinders in the 20s. https://en.wikipedia.org/wiki/Sound_recording and my own large collection of 78 rpm records dating back to 1910 ish.

There can be confusion over terminology here. In the UK, phonograph applies exclusively to cylinder machines. In the USA it could apply to disc machines as well - but no-one was issuing cylinders that late or using them for sound capture prior to re-recording onto disc. Discs were recorded directly on wax disc until tape came in in the late 40s.

For the benefit of the CD/DVD generation, discs were flat grooved shellac or vinyl (very much later) records that originally were single sided, and then double sided. Cylinders were literally cylinders, fitted onto a spindle with the head tracking straight along as the cylinder played. Cylinders were single sided of necessity, the sole exception being one in the Goon Show where the secret instructions were on the other side of the cylinder. As the Goon Show was on radio, this didn't present them with any problems...