To be honest, Nedim, at your age, I am not sure I would recommend starting a classical regime. If you are looking for a teacher, I would start by trying to find one that is on YOUR page when it comes to the music you WANT to play. A straight ahead classical teacher knows very little about the needs and demands of a pop or jazz musician, or has much respect for what YOU want to do, sometimes.

But it is quite possible to check out if any teachers in your area actually gig, and if they actually gig, what stuff do they play, and maybe go out and listen to them. At which point, you might be able to decide for yourself if THAT teacher is the one for you... If they got great chops but can't swing their way out of a paper bag, how's that going to help? But maybe if they are a BIT less technical, but their playing affects you emotionally, that might be your best bet.

When I first started piano lessons, I had about a year or so with a strict classical martinet. But I KNEW that that wasn't what I wanted to play. So I got my parents to hire a local cocktail pianist that played in one of their favorite restaurants. He taught classical as well, but wasn't a GREAT player. But he knew about chords, jazz voicings, improvising, playing by ear, all the things that classical players never tech you. But he had enough classical training to know what exercises WOULD be needed, and which were just overkill.

That man put me on the right path, and I never looked back. Sure, I can't rip off a bunch of Rachmaninoff off the top of my head. But I've made a living playing music at some quite high levels based on the practical stuff he taught me.

It's not easy for adults to go back to square one and re-do everything. I think, at this point, studying under someone that shares your musical views is possibly a better path than studying with the best classical teacher in the world...
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An arranger is just a tool. What matters is what you build with it..!