The PIMA arpeggio pattern is very common, and is one of the more useful patterns to practice.
You could write this P-I-MA
So the end result is this:
- P plays, alternates with I
- I plays, M and A throw
- M plays
- A plays, alternates with P
The Common PIMA Argument:
Another way of doing the PIMA pattern would be to throw all three (I, M and A) when the thumb plays (P-IMA). And this is fine. You won’t “get in trouble” if you play it this way. The Arpeggio Police won’t shine flashlights in your window.
Nonetheless, there are benefits to thinking of it as an IMA pattern with a P in front (P-I-MA).
Benefit #1: When practicing to ingrain good fundamentals, it’s helpful to make demands on your hands that require you to stay focused and aware of what you are doing. Playing with the added complexity (P-I-MA) connects more synapses and trains the hands more effectively than with the simpler version (P-IMA).
Benefit #2: Next, it’s easy to get going too fast when playing the P-IMA version. This leads to a lilting rhythm. Many beginners try to attain a “perpetual motion” type of movement, not realizing that this is only accomplished by properly ingraining the movements first, and even then with massive focus and direction.
Benefit #3: Lastly, and perhaps the most pragmatically, when you throw I, M and A all at once, and plant them on the strings, you effectively mute out all three strings at once. This doesn’t matter if you are starting from silence. But if you are playing a repeating pattern, this will mute out the sound too early, and undermine the beautiful, flowing effect of the arpeggio pattern. Playing it as described here (P-I-MA) allows for the strings to continue ringing for longer, which generally sounds better.
However you go about it, consistency of tone and rhythm should be your main focus. It’s worth your time to ingrain this pattern slowly and intentionally into your muscle memory. You will definitely see is cropping up often in your pieces.