Hi Christian, ok so you’ve been playing your alto sax for about a year and a half, you are doing really good. I can hear some confidence in your playing, especially fingering and on at least one embellishment which was a mordent I beleive.
Two of the most important things to work on now:
intonation and timing.
these are very common things beginners need to improve apun, once starting to develop the embouchure as you are doing.
For tuning, simply work with a constant pitch and spend time trying to match it:
How To Tune a Saxophone Properly
Ac for timing, this comes with more experience and working hard in listening to others;
while practicing with the backing track (this is a good way to practice), listen more to the other instruments as you are playing your part.
your foot should be tapping along with the beat, this helps us not to rush ahead (or fall behind) wit you I heard it more as jumping ahead of the beat.
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