By “core repertoire”, I mean pieces that you’re pretty sure you could play from memory, without rehearsal or access to the score.
Here are mine.
Bach - Prelude in C Major, BWV 846
Bach - Prelude in c minor, BWV 999
Handel - Sarabande in d minor, HWV 437
Chopin - Prelude in e minor, op. 28 no. 4
Chopin - Waltz in a minor, B.150
Debussy - The Little Shepherd
Satie - Gnossienne no. 1
Prokofiev - Repentirs, op. 65 no. 5
Nyman - The Heart Asks Pleasure First
Pretty much just Cat Steven’s “Silent Sunlight” for me at this point. For quite a long while I could play Scott Joplin’s “The Entertainer” from memory but after an interval when I had no access to piano it has faded from memory so I retain parts but not the whole and I just haven’t been bothered to re-memorize it entirely.
While I can see why committing music to memory is useful for formal performances I have no interest in that aspect of playing as I play solely for myself in my own home (occasionally my sister’s home - she has a piano, too). As I have never had a reason to memorize or routinely play piano music from memory I never acquired that skill. There is no reason I can’t keep the music in front of me and occasionally glance at it as a reference and memory prompt. I’ll generally have a LOT of a piece memorized, but not all of it.
Pretty sure if I had to or felt motivated I could memorize piano pieces - lord knows I used to have a memorized repertoire on bagpipes and the drums when I actually was performing using those instruments - I just don’t feel a need to do so for playing piano at this time.
This is probably because I am entirely self-taught on the piano and never had a teacher standing over me requiring to memorize music pieces. I’m sure that meant I took longer to master some skills than I might have otherwise, and I did have to remove some bad habits I acquired when young, but my playing makes me happy, which, as an amateur, is really the point.
I find it a little disturbing how seemingly quickly I can lose a tune if I haven’t played it regularly.
However, there are a few that seem as if they will be with me always:
Hmm, guess there are more than I thought.
mmm
My first piano lesson was in 1978: over the years I’ve only memorized a few pieces, and right now the only thing I could play without sheet music is Journey’s “Faithfully” (and I could stumble through a short Bach piece whose name I don’t think I’ve ever known). I’ve never been a performing pianist, so I have no need to memorize anything. I definitely have muscle memory associated with some of the pieces I’ve been playing for decades, though.
Eh, I took classical lessons for several years and was never required to memorize anything. 
Sight-reading is an essential skill for a classical pianist, but I’m not good at that at all. So, I memorize pieces, otherwise, I’d have to re-learn them all the time. On the other hand, my ex took formal piano lessons for over a decade when she was a kid/teenager, and she could play all of the above pieces on the spot, discovering the score as she went along, basically as if she was reading a book aloud. One thing that I found fascinating was when she realized that the fingering she had chosen was not optimal. She’d discreetly change it without missing a beat and carry on.
I learned to read music the same time I learned to read English, and I read it easily, but first-time sight reading and on repeat. Definitely, that has impacted me in that, with music in front of me and ease of reading it, memorizing wasn’t necessary. Those who read music poorly or not at all would have more reason to memorize.
I’m self-taught from an early age. My older sister, with many years of classical and jazz piano lessons under her belt was quite good. Some of that must have rubbed off on me.
I can read music, but mostly played by ear. I was good enough to play in a band (piano, organ and synth) in my college years for pocket change, but haven’t played in well over 20 years.
I’m fairly confident I could still play an odd assortment of a few tunes from memory if I had to, like Funeral For A Friend/Love Lies Bleeding, Spinning Wheel, Superstition and some easier Bach, Beethoven and Chopin. Also pretty sure I could still improvise some boogie-woogie—that was my favorite.
Now I want another piano.
These are the pieces that I can play through with the music in front of me. Take the music away, and I’ll have memory lapses. I want to nail these down.
I’d love to play his Mazurka in c# minor, op 63 no. 3.
I used to be able to play his Two-Part Invention, no. 2.
Wonderful stuff, definitely at the limit of my abilities then, out of reach now. I plan to relearn it, though. It’d be great to have at least one contrapuntal piece in my repertoire. Perhaps next year.
I’ve had the score for years but I never gave it a try. I’m learning the first movement of the Moonlight Sonata for the moment, which is going to keep me busy for a while.
@Moonrise - yes, there’s so many great Mazurkas. I can sight - read most of the Opus Posthumous (mostly written when Chopin was a teen).
Fur Elise - the main theme is really easy - amateurs love it because the two hands never play simultaneously. However, the B and C sections will be a shock - they are not so easy.
There’s nothing from my classical days about 35-40 years ago that I can remember. I can play the first eight bars of a number of pieces but then, forget it. The best I can do is the Maple Leaf Rag up until the C section, where I completely lost the muscle memory. The rare times I play these days, I mostly noodle or pick out songs off the radio and improvise to them. I tend to make up songs, though occasionally I’ll go through my Fake Book and play something like Satin Doll, Take the A Train, Misty, etc. But it’s been about 20 years since I’ve played anything “seriously.”
I should add a few jazz standards to my repertoire, too. I could play Autumn Leaves and Somewhere over the Rainbow at one point but I’ve forgotten them. I once gave Puttin’ on the Ritz a try but couldn’t get it to work.
@K364 I forgot to add : the c# minor is my favourite Chopin waltz, but it’s too difficult for me.
My mother made me take lessons as a kid and the only thing I remember how to play is “The Muppet Show Theme Song.”
Joplin is so much fun. The only downside is that Mr. Joplin had considerably larger hands than I do so occasionally I have to modify some things that I just can not physically finger (yay, music theory!) I started with “The Entertainer”, moved on to the “Maple Leaf Rag”, and the third I played a lot was “The Cascades”. I’ve toyed around with some of the others, but those were the ones I really worked at playing well.
Yes. My experience with “Für Elise” went something like this:
First movement: Oh, this isn’t too bad, it’s kind of fun
Second movement: Whoa - WTF? Hey - this is hard
Still enjoy the challenge of working on it.
I’m getting rusty again because I’ve having some issues getting my piano fixed, but eventually I’ll have a working one again.
Bah. It’s much more challenging and satisfying to be able to produce a beautiful piece of music without a cheat sheet in front of you.
mmm
Reading is not cheating.
Reading enables me to play music I have never heard before. Granted, less of an issue now than before the internet made most music easily accessible.
I play to please myself, not to win some sort of challenge or one-up anyone else.
A fellow soul! In the past I’ve learned hese two by heart
That basically where I am - I get to a point where I have long passages memorized but I still need the music to prompt my memory.
Indeed.
But sheet music, for me, is for learning a piece, not for playing a piece.
mmm