It's a painful process that may not even be perfect no matter how much time you invest.
It doesn't have to be that way, though, because LALAL.AI actually uses artificial intelligence to separate vocal and instrumental tracks for you. Not only does it require virtually no effort on your part, it only takes a few moments to create downloadable versions of each track.
It's really not much easier than using LALAL.AI. You simply go to the website, upload the song you want to split, and wait a minute or two while the AI processes the file and outputs the split version. Compared to spending hours in a program like Garage Band manually splitting tracks, using LALAL.AI is a no-brainer.
Once the files are separated, you can listen to them directly in your browser or download the separated MP3 files to use them however you need. It's as simple as that.
When you play the files on the website, you can actually see the waveform, which gives you a visual idea of how the tracks are divided. It's quite easy to spot instrumental parts of the song, or places where there are heavy vocals and less background music.
I tested LALAL.AI with a few different songs, and the results were consistently good. I threw easy pop songs into it with clear distinctions between vocals and instruments, and it handled them with ease.
To really put it to the test, I tried a song by technical death metal band Gojira, which is musically very complicated. It also features loud, screaming voices, which I think would make it harder for the AI. However, the separation was as good as with simple pop songs.
Of course, it's not perfect. Without having the actual master tracks, it's almost impossible to get a perfect split between vocals and instruments. However, it does a really solid job.
If you're trying to learn a song and want to focus on voiceless instruments, LALAL.AI will do the job well. On the other side, you can also use LALAL.AI to sing a song without hearing the original singer. Their voices will sometimes appear faintly in the background, but if you sing the song, you won't notice it at all.