Alfred Adult All-in-One Course Level 2 and 3

Player1 And while not everyone can sling the lingo like an auctioneer can, that doesn't mean you have to live life in the slow lane chanting at a walking cadence either.

Good point P1, maybe there is some middle ground to be found and if I don't try I'll never know. I've not yet encountered a piece which includes 16ths, but I've worked on the chromatic scale and there are a couple of pieces in book 2 which feature nice chromatic runs. Those things can be included as part of my practice routine.

I'm currently playing the BF Polka as a warm up piece each day, trying to pick up the speed a bit. When played by professionals those note runs sound quite impressive, and the piece is cheerful (helpful as we go into winter, when my mood dips).

While I agree with practicing at tempo well below one's own threshold does nothing little to help gaining speed, the real question is what is that threshold and where to play around that threshold.

In my limited experience, the speed thresholds is when I begin to make occasional mistakes. If I begin to make same mistake in repeated runs, or I feel I am losing control, then that's above the threshold - time to stop and reduce the tempo! Even at the threshold, where occasional mistake happens at random slip of mind/finger, I still find prioritizing accuracy (by a couple clicks down on my metronome) is much more effective. When practicing just below my threshold, accurately and in control, for a little while, I can usually raise the tempo back up a few clicks and achieve the new speed still accurately and in control. Rinse and repeat that, is what I find the most effective way to raise speed.

In addition, scales & arpeggios are different because there mistakes generally means wrong or missed note. When practicing pieces, occasion mistakes does not mean just wrong notes. Even after I can play through a piece at tempo, I have often had to slow down to get articulation, dynamics and pedaling right before adding speed back again.

iternabe practicing at tempo well below one's own threshold does nothing to help gaining speed

I am also in the disagree camp, here. My current piece is a slow Blues and I practiced it very slowly. I got faster and faster from alone. I even did not want to speed up. Now it is too fast and I have to concentrate to keep my tempo slow during playing.

Edit: this is when practicing without metronome. With metronome you have indeed you increase the speed from time to time. But only when you can play it errorfree enough.