Is it true that the thumb should be always on top of the piano keyboard when playing?

Question

Piano teachers often say that the thumb should never be outside the piano keyboard, that is : the thumb should always be above the piano keyboard.

I'm not sure if this is correct. I give a counter-argument : if one play dominant 7th arpeggio on C on two octaves for example, on the left hand four first notes, my thumb is outside the keyboard : this is only on the G that I put it : the reason is that in order to have the important extension for this space of fingers, I need to rotate my left hand a bit to the right, thus my thumb naturally is outside the keyboard

This looks almost impossible (apart if one has giant hands) to avoid having the thumb outside the piano keyboard for a non negligible time.

Is it true that the thumb should be always on top of the piano keyboard when playing ?

Answer 1

I have never been particularly aware of whether my thumb is over the actual keys or not. In my view you should do whatever works for you.

As a piano teacher I would want beginning students to keep all their 10 fingers above the keyboard, and I would correct them if they were to play so close to the ends of the keys that the thumb was too far away. When passing the thumb under the hand it should not be so low as to need to be beyond the edge of the keys.

I regard this as good general advice, but not a straitjacket.

The advice certainly does not apply universally to keyboards generally; there are organ works where the thumb is used to play a note on the keyboard (manual) below the keyboard being played by the other fingers.

Answer 2

Yes and no. Your thumb can go anywhere if necessary. But generally one requirement for speed and fluency is to have the fingers right above the keys they need to play, so you only need to press down the key without having to move the finger into position first.

Now, if you hold your hands straight the thumbs will not make it onto the keyboard, so anytime you want to use your thumb you need to change the hand angle, which will drastically limit your playing. Instead the default position should have the hand slightly angled in such a way that all fingers are at the necessary position, ready to just press down when you need it. This is why a piano teacher would put emphasis on such things when teaching a beginner, so that the student develops a good posture.

Once you have a good posture this won’t be a thing anymore. Most of the time you’ll stick to it naturally, and when you don’t there might be good reason not to do so.

Answer 3

While there can be occasions where one's thumb is away from the keyboard, it's a good idea to consider fingering to see if there's an alternative that allows the thumb to stay in better position.

In the case of the left hand, use the fingering 3-2-1-4.

C E G Bb C E G Bb
3 2 1 4  3 2 1 4

With this approach, the thumb can stay in position over the keys during the 3-2-1, and since now a longer finger will handle the Bb, the thumb will stay naturally over the keys as well.

Another option, in general situations, is to position one's hand closer toward the fall board. Applying this is the C7 case would allow for using a 5-3-2-1-4-3-2-1 fingering by positioning the hand so that the thumb starts off in position of the Bb. This avoids the need for twisting and rotation, provided one is able and comfortable having fingers 2 and 3 playing in between black keys. (However, in this specific case, I still recommend the alternative fingering, which gives smoother execution regardless.)

The GM7 chord presents the same problem. It's address, with photos of the hand position, in Piano: Left handed Gmaj7 chord.

Answer 4

Just tried that. On the way up, my thumb stays happily above the keys for the change to the second octave, but on the way down, it seems happy to move away, towards me, thus not over the keys at that same change point. Don't think I've ever been told that 'rule', and certainly not mentioned it to any student.

Answer 5

Just a few thoughts: Know that a teacher (and internet teachers) only know what they know and they don't know what they don't know, you know? We all think what we know and what we were taught is gospel truth.

First, the thumb isn't a finger and doesn't attach to the hand the way the fingers do. It is attached to the side of the radius and often when playing down, many teachers teach students to use the thumb's abductor which is its weakest and most sluggish muscle. The thumb's strongest muscle is its flexor but it curls the thumb under the palm and is designed for gripping. When the thumb is curled under the palm for many people it intersects with the index finger's long flexor tendon and can cause grinding damage. There are several disorders which can occur by curling the thumb under the palm such as distal intersection syndrome or Linburg-Comstock Anomaly. Also, curling the thumb under the palm creates a tension called a muscular co-contraction. Some teachers teach pianists to use the thumb through pronation or forearm rotation while others teach to play the thumb straight down using gravity or arm weight. Some advocate a tilt while others suggest a forward shift. I personally subscribe to using all of the above simultaneously to avoid any one muscle to be used twice in a row.

An example of teachers not knowing what they were talking about is Bach. He was a virtuoso whose technique came natural to him. He didn't know how or what he was doing so he taught his students what he felt and he felt his fingers caressing the keys so he taught his students the carrezando method. What he was actually doing was moving in/out/up/down and he felt like he was caressing the keys as his arm moved his hand across the keys, his arm was doing all the work and his fingers were not doing much and it felt like carrezando. Playing carrezando can facilitate flat finger playing which can lead to long flexor tendonitis and median nerve entrapment.

As far as the thumb being off the keys, all your fingers and digits are different lengths which SHOULD require the pianist to play with an in/out motion. Curling them to equalize them creates tension*. So when playing a five finger scale, the thumb plays and when the index plays the arm moves out because the index is longer, the middle finger moves the arm and hand further out. This will take the thumb off the keys then there is a shift forward to play the shorter ring and further in for the pinky. When the thumb is off the key, it should never drop below the keys and instead remain naturally and relaxed next to the index. When you allow the thumb to drop below the keys, it throws off any rotation and gravity of the arm and hand. Up is very important because you can't play down on the next note if your weight is hanging down. Your arm can only move in one direction at a time and if the thumb is pulling down the arm can't play up. It is like walking up stairs, your foot raises higher than the next step then comes straight down. If you don't lift your foot high enough you will trip up stairs. Dangling the thumb below the keys will throw the balance of everything else off. It also behooves the pianist to play on the outside edge of the keys because they are a fulcrum and thus, lightest on the edge and heavier the further in you play.

*With all five fingers together, wave bye bye. It should be effortless. Now curl and make a claw with your fingers and wave bye bye. You will probably feel strain. Likewise, abduct (spread out) all your fingers and wave bye. More strain. A lot of teachers will then tell their students they need to practice more, prescribe a silly exercise or tell them they need to build strength and endurance. I suggest they cease moving improperly and the strain will go away. Another fallacy is to tell the student to relax but, relax what? If you relax the muscles you are using to play, you can't play. Instead, relax the wrong muscles and employ the proper ones.