It will be beneficial to learn some music theory.
In that way you'll be able to identify repeating patterns (like the II-V-I chord progression).
It is easier to memorize larger chunks, so learning how to identify patterns by e.g. chord function should make it easier.
music.stackexchange.com/users/8682/Meaningful Username
Someone asked about a good way to remember song lyrics in this thread : Good way to remember lyrics when covering songs?
I shan't repeat everything written there .. if you're playing an instrumental some of the techniques may still help!
I've found that just listening to a song a lot
so it's settled in your head
works very well.
Also there's a kind of quantum jump after listening to a song off and on for a week or so..
maybe it's subjective but for me after several days
it kind of sits more deeply in the mind
and I can get to grips with it more easily.
The other option is to have some cues written on a card, maybe just the structure of the song etc.
That brings me to another point which is to try and visualise the "landscape" of the song - eg
is it verse chorus verse chorus wird bit chorus (repeat to fade haha) .. or something more unusual ?
hope this helps.
music.stackexchange.com/users/7337/user2808054
My cello teacher suggests this method for memorizing sheet music: 1) memorize the music in your mind, as sound 2) memorize the music as written on the page 3) memorize the physical motions (in my case, bowing and fingerings) 4) merge the three memorizations.
This may not apply directly to lyrics, but it's worth a shot.
music.stackexchange.com/users/6275/Carl Witthoft
What I do is: Compose the song
Play it some times, so to be able to play it without much thinking
write it down
(as tab/notes whatever)
(this helps me if I forget something after some time) Play it again and again on a daily basis.
I think the last part is the most useful of all.
You just have to play the song(s) over and over and over to remember them.
This will take some time, but it will work.
If you have a lot of songs and you get them mixed by mistake when you play, start off by writing them down and then for a few days just play 3-4 of them.
Then for some days play some other songs etc.
Also, it might help to remember a pattern of the song.
Like a small drawing that your fretting hand is doing while playing the song.
This has helped me memorize songs as well
music.stackexchange.com/users/7356/Shevliaskovic
I like to write down my music in tab notation software such like Guitar Pro or Tuxguitar.
Over time the collection of your own stuff will grow, and if you can browse through your songs simply by playing them back, it's a pretty good solution for me.
music.stackexchange.com/users/9626/strudelkopf
I've found that using a different notated representation can help.
In particular, sheet music often makes it hard to see the wood for the trees; the amount of detail can obscure larger patterns (repeated or trivially different phrases, elements of form, etc.)
in lyrics, melody and harmony.
The act of actually creating one or more "song maps" at coarser levels of detail helps me to notice these patterns if I haven't already.
Then using them in rehearsal along with the sheet music helps me to remember them afterwards.
I'll see if I can dig up an example of one I've made before and add it later.
music.stackexchange.com/users/817/shambulator
Practice.
Not trying to be snarky, that's really just what needs to happen.
Additionally, I find it helpful to try to dispense with sheet music as soon as possible.
Playing songs as quickly as you can (even ones that are meant to be slow) helps force internalization.
But the main thing is practicing.
There's no substitute for that.
music.stackexchange.com/users/9639/imallett
I've been googling and, unfortunately, coming up short in search of techniques, methods, systems or just simple tricks for how to memorise songs. I'm currently on a writing spree (I play the guitar and sing over it) and have found that it can be hard to keep everything in order in my head.  So what I'm looking for is any and all tips on how to learn multiple songs, but also how you can efficiently go about learning each of them.
Tricks and techniques for memorising songs
music.stackexchange.com
<guitar><voice><accompaniment><lyrics><songwriting>
music.stackexchange.com/questions/15642
music.stackexchange.com/users/6870/nyaray
There are a number of option for learning multiple songs. Using cue cards is one.  Writing them down and practicing 3 or 4 of them over a number of days is another. Write down your music in tab notation software such as Guitar Pro or Tuxguitar. In the end,  you just have to play the song(s) over and over and over to remember them. One way to learn multiple songs will be simply to practise. However, other things that could help include writing down cues or parts of music or learning some music theory.
Learning some musical theory may help solve this problem. Writing down different cues or parts of music can help you to learn multiple songs. One way to better remember songs is simply to practise.