Got a performance coming up? Need to learn a song fast? It's one thing to memorize a song you've been hearing for months or years, but a new song that you're trying to cram into your brain over weeks or days will take some specific practice. Who knows, with these suggestions, you may be able to get the song down in hours, depending on the complexity and length of the lyrics.
I've read so many different tips on memorizing songs for my performances. Most of them work, but some of them work extremely well, so I'm going to put this list in order of what was the most helpful to me to what was the least helpful. All of these methods helped a bit at the bare minimum, so try them all and see where you stand with them.
I'm sure you've played the song you're trying to memorize enough to be able to get some of the words and melodies right. The key to really getting it memorized is to actively sing or play your part over and over, along with the full recording. Don't start doing the karaoke or version without music yourself. Perform along with it several dozen times.
If you are a singer, try humming along with the melody several times before adding the lyrics. Melodies often get stuck in one's head first, so make sure you have the complexities of all the parts of the song down, then start practicing the words by themselves.
If you're trying to memorize an instrumental part, hum the line several times along with a recording instead of playing it through.
When practicing the words, try practicing them at varying tempos. If it's a slow song, read the words over very fast, then mid-tempo, then slow. If it's fast, speak the words very slowly, then mid-tempo, then fast.
Get emotionally invested in the lyrics that you are trying to memorize. See if the lyrics remind you of anything that you can easily cling to in your personal life. Does the lyric remind you of something you've been through before? Maybe it reminds you of a friend or family member? Whatever that connection is, really dwell on that memory or person each time you hear or perform the song.
Keep the instrumentation and the background vocals in the recording if you can, and just perform the lead part as you read the lyrics and/or notes. Really get a feel for how you will perform if vs. how it may have been performed by the original song performer if it's not your original work. The more you get a feel for how you will uniquely perform, the more the song will stick to you.
Once you really start feeling confident with how the song goes, challenge yourself by attempting to do the song in reverse. This will really help your brain retain the memories of the song structure, melodies, and lyrics.
Parts like the chorus will begin to come very easy to you, but some tricky areas like the bridge may still not stick. Practice sections over and over until you find yourself just singing that one part of the song at random times in the day.
If it's a singing part and not an instrumental part that you're trying to memorize, try singing the part with and without the original recording while you're doing something else like cleaning or driving. This will allow your brain to retain the lyrics and melody like second nature and will help you recall the song elements more naturally instead of feeling forced to anticipate each line.
If you're really tripped up on the text, try writing it down. Typing it out on your phone might help, but the act of writing will really help you connect the words you are writing with your brain.
If you're into sheet music, visualizing the lyrics and the notes by writing your own staff notes and lyrics will be even better. Writing the notes will help you memorize the melody line if you're having trouble with a complex melodic structure.