To me, the argument for memorizing from the start make the most sense. But you wouldn't want to do this with every piece or your reading skills will suffer. If you're only memorizing an occasional piece, problem solved.
It would be an interesting experiment to take two similar pieces (you obviously couldn't use the same piece) and memorize one from the very beginning and the other only after you'd 'learned' from the score, and see which approach worked best for you.
keystring On the I IV V type of analysis. This is helpful if your music is rather diatonic. Like IV are the 4th, 6th, 8th note of a major scale in that key - in a minor key you could have IVm (or iv). But what if the music uses notes and chords not in that key (so, not diatonic)? Although very often we do have these, maybe with others interspersed: I (stuff, stuff) IV (other stuff) V - kind of like a rough framework of the general path of the music.
But then, even if your music does have that kind of structure, you have to already know them - you must be able to recognize what key the music is in (at that moment) and be able to recognize those principle chords.
I think you have to know Roman numeral analysis beyond I through V7. Being able to recognize secondary dominants, for example, will help explain notes not in the key signature.
keystring The pattern starts: Em7b5 (half diminished), E7b5, Eb7b5, Eb7 ...... new sequence: Gm7b5, G7b5, F#7b5, F#7 ... new sequence Bbm7b5.... etc.
Or the pattern is: half diminished chord (Em7b5), raise the 3rd so G to G# for the E7b5, do that same chord a semitone lower, turn it into a straight Dom7 (E7) by raising the 5th ..... do not resolve E7 normally (would be to an A) - instead start the whole cycle again starting a major 3rd higher.
This does not work for my brain. At all. 
When I watched the video, in the selections the RH seemed to have some kind of melody or melodic passage, and I'm assuming the LH was more of an accompaniment. I'd do HS or HT depending on the nature of the music.
In one spot he identifies a chord as missing the 3rd, then states that with the LH it would be a different chord, but he's ignoring that part. I didn't quite like that. For one thing, music often does have common chord progressions and these help make the music predictable for memorization.
I don't know which chord it was so I'm inventing one where in the RH chord the 3rd is left out. In the imaginary chord we're in F major, and the chord including the bass is C7b9 going to F (C E G Bb Db). Our RH notes are E G Bb Db which is a fully dimininshed chord (Edim7) But the 3rd is left out so we have E Bb Db. -- with the LH we'd get C E Bb Db. Is it easier to memorized Edim7 to F ..... or C7b9 to F? I'd say the latter because of V7-I. In fact, the C7b9 would help me remember the E dim7 (where we're assuming the G, btw.)
I'm ambivalent, because I have run into this, where the LH gave the actual chords, but I saw a clear pattern via the incomplete chords for RH alone which actually helped me. I think I preferred to perceive both.
Stub I think you have to know Roman numeral analysis beyond I through V7. Being able to recognize secondary dominants, for example, will help explain notes not in the key signature.
Exactly.
Stub This does not work for my brain. At all.
I got the patterns physically - it doesn't work in writing. I've been aware for a while of turning one chord into another by altering a single note which is like sliding a finger over: C to Cm is a simple example where you just slide the middle note over to the black key. Finding the four part pattern physically and with the ear makes it easy.
The main point was that this is an extreme for of not being diatonic with I IV V type chords, but there are still patterns. By pure coincidence I just happened to work with this.
Memorizing music doesn't have to be forced. If you know a tune well and how the LH accompaniment is put together, you can sit down and play it without thinking about the song or practice it for a week to get it into your head.
There are several Pop songs I've learned that are arranged in a simple way. Once I was invited to a gathering and played a Pop song by ear without the sheet. It's not my favorite song but nonetheless the arrangement is very simple with LH arpeggios throughout. Once you learned the sequence, the rest are just repetitions.
There was a video by the piano teacher Jazer Lee from Australia. He said that people who appear in a talent show like "America's Got Talent" or "Britain's Got Talent" wouldn't perform on stage with sheet music. Otherwise the performer would look unprofessional.
When I started learning violin in strings class, everybody around me had to learn to read and played from the sheet. I assumed this is the norm but soon discovered that I was a natural memorizer. Over the years I've seen many student performance videos. Some are really good readers. Their eyes are locked to the sheet while playing expressively. Others play well without the sheet. When I was young, I thought that reading off the sheet was the only way to play pieces. Over the years I've played pieces at gatherings and on public pianos without reading a note. Today I'd play mostly from memory although I carry a lot of music PDF files on my phone just in case.
Depending on the way a piece is arranged, some pieces are just easier to memorize. Anything with a lot of repeated notes, chords or intervals is easy to remember. A piece like Bach Prelude in C out of WTC Book 1 is an easy piece to memorize simply because of the repetition. A piece out of Bach 2-part Inventions such as #4 or #8 is challenging to remember dispite playing just 2 notes at a time (1 on each hand). A piece like the Bourrée out of Lute Suite #1 (BWV996) in "First Lessons in Bach" is relatively easy to memorize. The piece has 2 lines (1 for each hand) except for the ending chord..
Stub To me, the argument for memorizing from the start make the most sense.
Oof, unless it's an easy piece, for me there's way too much risk of learning the wrong notes! I think I would want to be at least comfortable playing with the score (maybe not at speed, or still having some technical issues, but at least being quite familiar in my fingers) before adding memorization as an additional step.
Of course we all have different strengths and others who are more aurally focused might find it easier to get away from the score early on?
Stub It would be an interesting experiment to take two similar pieces (you obviously couldn't use the same piece) and memorize one from the very beginning and the other only after you'd 'learned' from the score, and see which approach worked best for you.
I might learn the Chopin "Cello Etude" from the beginning by memory. It's short (!!), I know generally how it's supposed to sound (although not well enough to play the whole thing back in my head) and the only challenging bits are places that I'd probably have to memorize anyway.
I think length, difficulty, and familiarity are major factors for whether I'd consider memorizing a piece at all, and if so, at which stage of learning.
thepianoplayer416 Memorizing music doesn't have to be forced. If you know a tune well and how the LH accompaniment is put together, you can sit down and play it without thinking about the song or practice it for a week to get it into your head.
What you're saying is for simple pieces but really doesn't apply to advanced works...
pianoloverus what you call read- playing which is commonly called just reading.
I have been trying to get people to use the term "read-playing" for ages!!!! I posted about it at PW dozens of time! 
To me, it makes a helpful distinction, but I get that no one else uses the term! 
twocats What you're saying is for simple pieces but really doesn't apply to advanced works...
Yep, I agree.
Even some "simple-ish" pieces, which are long and have repetitive patterns can be deceptive, once you get into them, the subtle variations would make it even harder to memorize (a lot of Einaudi is like that... 12 pages of subtlety... I definitely need the score for those!!)
Back to studying away from the piano: now that I've tried to memorize 9 "chunks", my goal is to be able to spontaneously recall the starting notes of each chunk. Once I start playing, finger memory will take over but I need to create the "landmarks" to really solidify the learning. I think this is a great exercise to do away from the piano as it forces me to learn it in an additional way. I want to be able to visualize where my hands will be at the beginning of each phrase.
twocats
A piece can be easy or hard based on the repetitions. Having few or many notes doesn't automatically make a piece easier or harder.
You can be playing intervals or chords that are repeted throughout the piece makes it easier. Some pieces can look easy without many notes but the fingerings can be challenging. Pieces with overlapping notes played with the same hand is more difficult to remember. A few years ago I learned a Sarabande from a Handel suite.with Variation A & B after the main theme. The main theme has chords that are easy to remember. Var A is a bit tricky because of overlapping notes where you'd hold a note and play others on top.
A while ago I learned a piano arrangement of a movie theme. There are a few chords & jumps throughout the piece. Otherwise it has a lot of repetitions that made the piece easier to remember. After a few weeks of practice, I was able to play it on a public piano with ease. 1 aspect of "repetition" is the music being repetitive. The other is you repeating phrases many times to lock in the notes & finger sequences (muscle memory(.
twocats Memorizing music doesn't have to be forced. If you know a tune well and how the LH accompaniment is put together, you can sit down and play it without thinking about the song or practice it for a week to get it into your head.
What you're saying is for simple pieces but really doesn't apply to advanced works...
And also depends on how secure you want the memorization to be. It's one thing to memorize a piece that you play just for yourself or for your teacher where a memory slip is not going to be so important versus memorizing a piece that you will perform in front of a lot of people In a recital or competition.
thepianoplayer416 A piece can be easy or hard based on the repetitions. Having few or many notes doesn't automatically make a piece easier or harder.
The piece I'm working on is RCM diploma level, ABRSM Grade 10. May I respectfully say that based on the pieces that you've mentioned, you have not experienced any of the challenges that you would face with advanced works and your comments on memorization are much too simplistic.
I just realized that I shouldn't have put this thread in the Learner's Lounge. I thought the topic was about "learning" but reading the description that area is for beginner to intermediate players and this topic is probably better suited for the Pianist Zone, so I'll move it!
twocats I just realized that I shouldn't have put this thread in the Learner's Lounge. I thought the topic was about "learning" but reading the description that area is for beginner to intermediate players and this topic is probably better suited for the Pianist Zone, so I'll move it!
I disagree. It is about learning and is an aspect of learning. The same principles that apply to an advanced pianist are ones needed at earlier and even very simple levels.
pianoloverus And also depends on how secure you want the memorization to be. It's one thing to memorize a piece that you play just for yourself or for your teacher where a memory slip is not going to be so important versus memorizing a piece that you will perform in front of a lot of people In a recital or competition.
This is also a really good point! I have never played in a competition, and the only pieces I memorized for recitals were a long time ago when I was playing beginner level music.... I think I mentioned above that the last time I had a few memorized pieces was when I was piano shopping, and I did that so I could audition pianos with the memorized pieces. Well, to me, playing in a piano shop is at the level of playing for a teacher, or maybe even less. Actually I was surprised to realize that I was not nervous at all when I was playing while piano shopping. I guess I knew that I was the customer, and I had money to spend. So it was a very different dynamic.
All that to say that I personally have never experienced playing an intermediate or above piece from memory in a high-pressure situation.
And I probably never will! 
I certainly will be playing from the score when I play my two pieces at the recital next month!
twocats If you look at the description of the tags, "Learner's Lounge" is specifically targeted to beginner to intermediate players. "Pianist Zone" is general piano discussion topics.
I understand. The topic is also relevant to beginner and intermediate.
I may start a parallel thread in the "learner lounge" and maybe refer back to this one. Most of the principles are pertinent and important. I also don't see the "learner lounge" as such categories. There was a problem in PW because of the "adult beginner" name, which did not fit a lot of people. We were "learners". I saw the "pianist" area as one where advanced pianists did advanced things. There are skills pertinent to all levels, which are more on the level of "learning" as opposed to how to play or interpret this advanced piece of music.
