So I know this forum is mainly for Euphonium/Tuba players but I figured I could still get help. I am a Junior High Euphonium player who recently took an audition for High School band placement(we have three ensembles) and was placed in the top band on trombone. They asked me if I would switch and I said yes because I have had a trombone for a few months and had played on it some. Having not expected to be switching I never took it very seriously and my slide positions were not learned and I have had lots of trouble staying in tune. I have a few months before I begin to play with this band so what should I be working on to improve my slide technique? I have mainly been working in the Arban book on articulation excersizes and scales. I also have problems cracking notes on trombone whereas I almost never crack my notes on Euphonium. Why am I having problems cracking notes and what can I work on to fix this issue?