I'm currently trying to learn scales, arpeggios, and thirds. For reference, I'm working on G major, Bb major, and D major, on the second page of scales at the end of the 2nd Standard of Excellence book. Trouble is this: I play through one set of scales (e.g. G) until I get it down and it feels right. Then I move on to the next set (e.g. Bb). Once I have this down, if I go back to the previous scale I was working on, I've forgotten all the hard work I put into it and start missing notes, mostly the ones that are specific to the scale. I might play a Bb instead of a B, or an F instead of an F#. Does anyone have any tips for getting these things down?