the thumb-under move for getting past five notes
last lesson we stayed inside five notes, right hand, one position, no moving around. that's on purpose. you needed your hand settled before we asked it to travel.
today we ask it to travel.
here's the problem. five fingers, five notes, and about a million songs need more than five notes in a row. "come thou fount," which I'll get to, needs more than five notes. so does almost anything that isn't a nursery rhyme. you can't just stop playing every time the melody wants to go up to the sixth note. you need a way to slide your hand up the keyboard without a gap, without a thud, and without looking like you're rebuilding your whole hand position from scratch every four notes.
the answer is the thumb-under move. it's exactly what it sounds like. while your other fingers are still playing, your thumb tucks underneath your palm and lands on the next note up, and now your hand has quietly relocated without the music ever pausing to notice.
what it actually looks like
say you're going up a c major scale with your right hand. fingers 1 through 3 (thumb, pointer, middle) play c, d, e. now you need f, and you're out of fingers going in that direction unless you do something.
here's the something: while finger 3 is still holding e, your thumb ducks under your palm, quiet, no drama, and lands on f. then fingers 2 and 3 follow with g and a. your hand has moved up one whole position and the melody never stopped.
that "ducks under your palm" part is the whole lesson. not over the top of your hand. under. your other fingers stay relaxed and slightly curled so there's room down there for the thumb to pass through. if your hand is flat and stiff, the thumb has nowhere to go and it ends up banging into the keys it's trying to get past.
which brings me to my one opinion for today, the one I'll probably repeat until you're sick of it: I don't think beginners need to worry much about "correct" curved hand shape for its own sake. it gets oversold. but this is the one spot where hand shape actually earns its keep, because a flat, tense hand physically cannot do a thumb-under. so if yours isn't working, don't fix the shape in the abstract, fix it because the thumb needs the room.
how to practice it at home
get the keyboard out, five-finger position, right hand, thumb on middle c.
- play c, d, e slow, one note at a time.
- while you're holding e down with finger 3, move your thumb underneath your hand and set it, silently, right over f. don't press yet. just get it there and feel whether it's comfortable.
- lift finger 3 off e and press f with the thumb, same moment.
- finish with fingers 2 and 3 on g and a.
do that whole sequence slow enough to think about it. this is not a speed exercise yet. you're teaching your hand a new habit, and habits taught fast get taught wrong.
then reverse it, coming back down from a to c, which uses the same move backwards, finger 3 crossing back over the thumb this time. that direction feels different in your hand and it should. give it its own practice, don't assume it transfers.
the honest caution here
your thumb is short and a little clumsy compared to your other fingers, and when people first learn this move they tend to either slam the next note too hard, because the thumb overcorrects, or they hesitate so long the beat falls apart waiting for it. both are normal. neither means you're doing it wrong. it means your thumb needs reps, same as anything else.
don't force it if your hand cramps. take a break, shake it out, come back. this is a small muscle doing an unfamiliar job and it tires fast at first.
"come thou fount" was the first hymn I ever played all the way through with both hands, and this exact move is why I could get past the first line without stalling out. nathan came in partway through, sat down on the stairs, and didn't say a word until I finished. for him that's the equivalent of a standing ovation. what got me there wasn't talent, it was slow, deliberate practice of exactly this thumb-tuck, probably fifty separate times before it stopped feeling like a math problem.
before next time
practice the thumb-under going up and down, slow, both directions, until your thumb finds the next key without you having to look down and check. once that stops being scary we'll put a real melody line on top of it.