When working on facility, it can help to group disparate pieces at one speed. Some of the etudes I practice are in fours, some are in threes.

Fours (sixteenths):

Bach prelude in D, WTC 1

Chopin Fantasie-Impromptu

Threes (triplets):

Moszkowski etude

Mendelssohn “Spinning Song”

Q: If the pieces in sixteenths’s are at 100 on the metronome, what speed should the metronome be for triplets?

A: Triplets (3’s) are really a small unit, we should go with sextuplets (6’s) instead. The metronome marking 67 (or really, 66.66666) is essentially the same speed for sextuplets as 100 is for sixteenths (4’s).

Sarah Deming: “100 BPM and your sixteenths are both dividing into the whole.”

4 times 100 = 6 times X.

Then solve for X.

400 divided by 6 equals 66.66666.

Thank you, Sarah!