I think my question has been partially answered before:
- How to play a song without making mistakes?
- Practice to avoid mistakes or practice to cover mistakes
I am happy to take it down if it is considered a duplicate.
I have been practising almost every day (I think I have missed out on a total of like 2 weeks) for at least 1 hour for a few years by now ("older" musician here, I am way beyond my teens), I am still making mistakes, even in short pieces that I've been playing for years (thankfully, I have patient neighbours), and it makes me feel like I am doing something wrong. I frequently go to my teacher's performances, and he often doesn't make a single mistake, even if his band plays for 3 hours or more! As for me, I can count the number of practice sessions where I haven't made a single mistake on the fingers of one hand, which is very disappointing after so many years of continuous work (not to mention my compositions are a lot shorter and easier).
I am updating my question to provide some additional data. I am playing (tenor/soprano) saxophone (and have just recently started flute), and I did not specify it initially, because I wanted the question to be helpful to all musicians, and because I do not think my problems have anything to do with the instrument I play.
It is also important to note that the mistakes I make are irregular, meaning I make mistakes in different places, so it's not a case of "learnt helplessness".
Since the very beginning, I have followed what is considered good practice hygiene by most:
- Itemising (playing a new piece section by section, until you get it right)
- Analysing a piece compositionally before and during play
- Playing very slow in the beginning (to the point where my teacher would say I had remarkable patience) to avoid "learning to always play wrong"
- Recording practice sessions and listening to them
- Listening to professional musicians (excessively) perform the piece in question or recording electronic versions of it otherwise
- Using a metronome
- Keeping a practice diary
Despite all that and being able to play all basic (and some "advanced") scales from memory, I still make mistakes, even when playing said scales (the mistakes are physical, like "fingers slipping", I have no trouble recalling scales and chords from memory without looking at the print-outs). They do not seem to come from lack of sight-reading experience or proficiency with the instrument, I would describe most as "mind blanks", which I thankfully snap out of immediately upon hearing them. I either stop or run up/down the scale/arpeggios until getting back into the next section (depending on how OCD I feel on that day, but I am trying to get out of that habit of "covering up", because it feels psychotic and not helpful in learning to play intelligently).
So it seems like I am doing most things right, but it doesn't seem to produce perfect results. I do not play pieces from memory (my visual memory is virtually non-existent) or by ear. I do remember some sections kinesthetically (some people seem to believe such memory does not exist), and I think that's the only component that might be causing problems (because if you play something automatically, your conscious mind might go blank for the duration).
Am I expecting too much after less than 10 years of playing (I am discounting my experience in an orchestra when I was at school, because I stopped playing while being at university, and I played a different assortment of instruments at the time anyway), and should I just continue "sucking it up", or am I missing some crucial components? I have tried asking my teacher and some other professional musicians what to do, but most have been playing for decades and cannot remember or relate to what I am experiencing.