Very much off topic, but I'll add my experience and may even get back onto the topic: as a boy I played piano by ear, then asked for lessons, which I hated. That put me off playing (my mum said I didn't touch the instrument for eighteen months), but I did then get into playing guitar, again, by ear. I still don't read music but as we had an electric piano in the house and I could bash out some tunes, I took lessons a couple of years ago, and found that playing from the sheet music was like playing a completely different instrument, and I didn't really get into it. Back to guitars: I do have a couple of clip-on tuners, so I'll see what pitch my scroll saw blades produce, and how well they cut at those tensions, to see if it's possible to set an optimum tension by this method. Regarding tight angles: if there's waste material (i.e. not cutting a single thin line), then I'll often back up into the waste and not attempt a turn, but come back into the corner from the other line. If the waste is outside the angle, then I'll loop around.