Let’s say you are working on a piece. It has fast passages, tricky shifts, and notes that are unknown. We all have that piece. It’s everywhere. You have to really break it down and practice small bits at a time. Let’s say you want to work on the fast passages. There are several methods to playing faster. You need to try them to see what works best for you. First, isolate a few measures. Actually take a few post-its and cover up measures before and after, above and below, so you won’t be tempted to move ahead. One method is the metronome method. Set the tempo at a speed you can play comfortably. Play the few measures. Then you crank up the tempo 1 or 2 beats at a time until you reach the desired tempo. I’ve always had a problem with this method. I’m comfortable at 70 and I need to get to 120. That means I’ve spent 80% of my time practicing slower than I need to and I’m not actually learning to play it fast enough. NOT that I’m saying you shouldn’t play slowly to begin, but when you’re ready to up the tempo, you need a practice method that works for you. The metronome method may work. But here’s another idea to try. “Divide and conquer”. Keep the music covered up so you’re only working with a few measures. Say you have 2 measures of 1/8 notes like this:
You have to play them fast. Break it down into 2 note chunks, play the first 2 notes at OR ABOVE tempo. Play them several times. Then play the next 2 notes at tempo. Play them several times. Now play the first two notes, count to two, and play the second two notes. Do this several times. Then put the 2 groups together and play at tempo several times. Now you have the first 4 notes at tempo. Go to the next group of 4, break into 2 groups of two, and do the same thing. When the second group has come together, play the first group of 4, count to 4, then play the second group. All at the correct (or faster) tempo. Eventually, you’ll leave out the “count to 4” and put all eight notes together. I like this method. I’m playing at tempo, with small groups of notes, taking a break between groups. It’s very intense practice and it’s another method to try out. Let me know if it works for you.