I get asked about this a lot. A new student will tell me they've heard that "you should keep your thumbs off the black keys." But in order to follow this "rule" they end up turning their whole hand in and awkward manner; all to avoid playing a black key with their thumb.
Well I'm here to tell you that it's easier than you think. Yes, you can use your thumbs on the black notes! In fact, pianists do it all the time. So why this apparent prohibition?
The issue only occurs when you play a scale. Let's make an experiment: Go to your piano or keyboard and play an F major scale with your right hand. Start with your thumb on F, and play F, G, and A. Then, reach your thumb underneath your hand and stretch it to play the next note in the scale, the Bb. Continue with your 2nd finger on C, 3rd on D, etc. to E and F. In other words, you're using the familiar C major scale fingering (1231234) on F major, which contains the Bb as its 4th note.
Now play it again, using the same fingering. Do you feel how awkward this is? By placing your thumb on the Bb and then continuing with the scalar passage, you've forced your hand to practically turn a somersault. Now play the F major scale again, this time using the proper fingering of 1234123. Much easier, right? Your thumb now functions as a "pivot" on the white note. This is why different scales use different fingering; to keep our thumbs on the white keys (which are physically lower). This method fits the shape of our hands better.
But what about all the times when you're not playing scalar passages? Now let's look at those situations. Try this: play a Bb chord with your RH: Bb, D, and F, all at once using 1,3 and 5. You may need to slide your 3rd finger up to the middle of the D, but it should feel natural. This is because you don't need to pivot anywhere. Your thumb is fine on the Bb and, in fact, feels good in that position.
Whew - I'm glad we cleared that up! We can happily let our thumbs land on the black keys in most music situations; except when they involve scales. Now let's get back to our keyboards and play some great music 🙂
By the way, click here if you want some fresh ideas about practicing scales. Have fun!
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