I was improving earlier...and honestly...it was good. Really good. My mom came out and complimented it which she doesn't do that often anymore unless it is really good.
But....I barely remember what I was playing. I mean, I remember some of the basic chord progressions and stuff, but all the runs and little things, they were just flowing, I wasn't thinking about what I was playing at all.
How do you guys who improv remember what you played?

I write it down.

I have a little voice recorder going. Or I use the "record" feature on my digital piano if I'm improvising on that. In a pinch, I've been known to use my cell phone as an emergency recording device (it's still got about 1/2 of a piano rag on it...)

Hi John,

Here's some food for thought. All those runs and stuff are decoration. Houses get decorated, but not before the house is built. Chord progressions, harmonic structure and themes are the foundation and structure of a piece. Consider this experience a lesson on what to pay attention to when improvising. Remember your themes and your basic harmonic ideas, then try to remember any special moments. If you do something that really impresses you, go back and do it again. When you're done write down what you remember and rebuild from there. Once you're good at it you'll probably find that the pieces you create are more substantial than your improvisations.

One thing I'll add is that my improvisations tend to be fairly safe. Stuff I know I can play and sounds nice. The pianos pieces I compose tend to be more challenging in every aspect.

I guess I need to get myself something good to record from my acoustic piano with. I'll look around.
And usually when I'm improvising, I'm putting whatever the most recent theory concept I've learned into practice, right now that's borrowed chords. My improvs usually have pretty good chord progressions because I'll think up to 8 chords ahead while playing in order to give a good flow. I need to start writing down these chord progressions and stuff, they're getting really good. My improv yesterday really did impress me, like...a lot. It's one of the first times I've ever really liked an improv I've done. Like enough that I want to take the time to figure out how to write it down. It'd be a pretty hella hard piece for anyone to learn also, I had some pretty intense stuff going on that I probably couldn't play if I were trying to read it off the music. haha.
I think whenever I improv I'll also make sure I have my staff paper sitting on the music stand so I can write anything big down.

I don't know if this would work but, can't you improvise on a keyboard that is connected to a computer. If you use a MIDI program, won't it notate it for you? I suppose it would be complicated, and not to mention, expensive, but it could work.

Technically, yes. But I'd need to play to an exact metronome and time signature, not to mention key signature and accidentals and complex rhythms. Technically you can do that but it just doesn't work that well. I tried that with one of my compositions I was having trouble notating, and the keyboard with sibelius got a lot of stuff really wrong because of me playing with the slightest rubato and other things.

Sibelius is a notation program. To record midi it's generally better to use a sequencing program like Cakewalk (even Cakewalk Express will work). It may not display the notes nicely but it will record the midi events perfectly, play them back exactly as you played them, and be a reasonable reference for when you get around to notating them properly.

I use a sequencer (Apple's Logic) during the initial phases of improvising, so I can save my ideas while I refine them. Then, I switch to Sibelius, and use the step-time feature for notation. It's not real-time, but it works fast, especially when using a numeric keypad, and it's not error prone.

I record it on Clavinova. But most of the times I try to remember it and then analyze, so that I won't forget what it was.

Improv again and try to feel the same way you felt when you're playing...try to get the same notes by ear...

personally i just try to remember what direction the music is headed, and i look at scales and stuff like little mountains across the keyboard

I record the MIDI using cakewalk. Two advantages of MIDI are that the files are very small compared to audio and you can see exactly which notes you played. If you record against a click track it is not too hard to convert it to notation although it usually ends up fixing the note lengths up so they will display nicely, particulary if you are playing legato.

Repetition, but that doesn't always work. There have been many a times that I have just played something awesome, but moments later I'm wondering to myself how to play it again. I hate that.

The MIDI idea sounds good, but that requires all the appropriate equipment. Something to look into.

I hardly ever improvise when composing, but I often do it just for the fun of it. When I do, I never write anything down, even though I might come up with something that sounds good in the moment. I reckon that if I forget it quickly, then it was forgettable and wasn't any good anyway. If I still can hear it playing in my head weeks later, then the material might have som merit and be worth to develop into a full piece. I have a few melodies in stock that I improvised years ago and still can hear note by note and the exact harmonies. Those I will most certainly use one day, just haven't found a suitable setting for them yet.