During WWII we had scrounged music from any source most often hand transposed it for the instrument we played. It was while I helped sort this that I encountered my first Arban's which my director said I could have as my own. Still, he never used it when he was tutoring me and for the longest time I just practiced segments on my own here and there in it. Maybe it helped me, I don't know, but I was playing 1st trumpet by the time I was a junior, the year my Director achieved his Doctorate in instrumental music from Carnegie Tech (now Carnegie-Mellon University). Who was my Director, now one can use a search engine for Walter H. Cameron and read basically who he was, and who he had once played with.
It is having lost my trumpets while in USAF that my major lapse began although with a rented Getzen I did 3 college years enough to pull a minor in instrumental music ... and they didn't use Arban's. Long story shortened, I bought my present Arban's when I began my comeback, and again segments of it are practiced daily along with my regimen, hymns, other music and my Cleffers' book. Cleffers is an open community group I usually play with on Wednesday evenings. I'm still in a sling following left shoulder rotator cup surgery thus won't play with them for several more weeks but will still attend to enjoy and pick up any new music (to add to my book(s) at $1.00 a song. Yes, I get them for trumpet and euphonium.) Occasionally, I now play a trumpet solo in several of the local churches amd I sound live Taps. I can still do the latter even with a sling.