I was wondering if I could theoretically take a part of a song with no vocals (ie the intro) and make a separate track with that part, and line it up with a part that sounds identical, but with vocals, and then invert it. Could this be done to make a “DIY” acapella of sorts? It would be interesting to try.
It would be interesting, yes. Use Track Copy (Control-D??) the Time Shift Tool (two sideways black arrows) and the various equalizer and volume controls.
There is a problem with cancellation. It doesn’t work with “Sounds Like.” For two sound tracks to cancel, they need to be bit-accurate and the waves need to be exact copies of each other. This limits cancellation tricks to the uncompressed formats such as Music CD, WAV and FLAC.
Most people want to do something like this with two whole tracks. One has vocal and one doesn’t. MP3s produce non-exact copies. If you change anything about the show, like add a voice, you’re dead. The violins behind the voice are going to be different than the violins alone. MP3 process knows about content, and can change it.
Just to be clear, it won’t work with lossless formats either.
For example, If you record yourself saying “Hello” twice and subtract one from the other, it turns-out that subtraction sounds exactly like addition. As Koz says, they are not bit-identical. Or as I often say, the difference of the sound is not the same as the sound of the difference.