Making acapellas
I’m trying to get an acapella of ‘Just Be Good to Green’ by Professor Green ft. Lily Allen, and I’ve got hold of the instrumental version, but inverting it and playing it with the original doesn’t seem to work at all, and I can’t figure out why. Can anyone help at all/is anyone any good at making DIY acapellas? Or, if you know where I can get one of this song, that’d save me a great deal of trouble 
I couldn’t find any versions of ‘Just be good to Green’ out there. But there are plenty of the original ‘Dub be good to me’ acapellas. Just google it!
Have a look at acapellas4u.co.uk.
…actually, don’t. They don’t have it.
Wasn’t there an article about making acapellas using the melodyne editor a few months ago? Something like that would allow you to extract your own acapellas though they wouldn’t be perfect.
Also, if you can find an instrumental version of the song then just load the original and instrumental into a sound editing program (audition or something like that) and invert the phase the of the instrumental, which then cancels out the instrumental from the original by way of negative interference… end result you have the acapella.
That’s true if the instrumental is an exact digital copy of the original minus the vocals AND both tracks are sunk up down to the sample. Also the volume needs to be the same. Hope this helps.
Didn’t work, as I said in my original post…
Oh wow, my bad.
Umm, is the instrumental a different length from the original? You might need to line the two up, original might be longer than the instrumental or vice versa.
Are you sure you’re inverting the instrumental and not the original?
Hmm, hell, are you inverting the phase of the instrumental track rather than the whole thing?
Also SirReal raises a good point.
Good luck with this man.
Is the vocal in the middle of the stereo image, and are the instruments panned left and right?
Same length… although I have just looked in Traktor and apparently they’re different bpms by about 0.004… any idea how to fix this?
Definitely inverting the phase, did it exactly the same way I made another acapella…
Uh, I don’t know… I don’t think so, what would be a good way to tell?
You could try extracting the center of the original track. Sometimes this seems to work, you can do it in Audition, but I’m not sure how. Google!
If the difference is .004 the BPMs are probably exact, that’s just Traktor’s read. At least, that would be my guess. I always round to the .0x number, as modern day dance music is rarely at a weird tempo like that.
Well, I did think that, but they don’t seem to line up in Audition - I’ll perfectly line up one beat, scroll through the track just to check, and pick a beat a while later and it’s completely out…
This is the best I’ve got so far, using a combination of centre channel extractor and kn0ck0ut… any idea how to proceed?
Here’s an example of what happens with inverting the instrumental… As you can hear, it starts off out of sync, then the drums fade out as they become in sync (‘tell me’) and then back in again. This suggests to me that the instrumental and the original are at different speeds, would this be a correct assumption? How can I fix this? I’ve got Traktor, Adobe Soundbooth, Adobe Audition, and Ableton live (although I don’t really know how to use ableton at the moment). I would REALLY appreciate some help with this, thanks 
You can play them through your DJ rig and get them in sync manually. Play the vocal at 0% speed change and sync up the instrumental. If it stays perfectly locked then “record” JUST the instrumental with NO EQ and try using that with the original to get your accapella. Keep the same bit rate sample rate. It still might not work if the rerecording colors the track at all. The other thing I would suggest is getting both tracks from the same source, ie beatport or some other Pro DJ audio site and from the same “release” I’m willing to bet one or both of your tracks have been processed in some way.
Already tried running them through Traktor and recording them both in sync with the master clock - it still came out wonky (won’t line up in audition, line up one beat and the rest are out) no idea why… both tracks are from the same source as well. Would ableton be better for making it less wonky? Traktor says the bpms are about 0.008bpm different
Might I inquire where you got the tracks from? Also, Like I said before, don’t use master clock. Just play the vocal version with no speed change. Change instrumental’s speed to match vocal and see if it stays locked with the vocal.
Got the tracks from iTunes.
Playing the tracks at the same time in traktor without using master clock does sound like they are coming slightly out of sync, but only very slightly… a bit like how the waveforms in Audition are slightly out of sync, but again, only slightly.
So are you saying they’re drifting out of sync or just aren’t quite synced perfectly with each other? Can you send me the files? I can check em out in protools and see if there’s anything I can do.