Syncing A cappellas: A Brief Introduction and Tutorial

1) What is an A cappella?
A cappella comes from the Latin phrase "In the manner of the Church", referring to songs that are performed with vocals only. This can include vocal 'instrumentation', in which voices are used to mimic other instruments and percussive sounds. In the world of electronica, the term A cappella is usually used to refer to the vocal stem of a given track, the vocal stem being the studio recording of only the voice.

2) Enough with the History, how can I Sync them to my Beat?
Since you would be here if you didn't know what you were using an A cappella for, let's cut the crap and jump right into the game, shall we?.
Note: I'm running FL Studio 9. Don't freak out if your interface looks different.

2.1) Set Up and Finding the Tempo of your A cappella
Load your project that you intend to use the A cappella with. When the project is located, find the A cappella in your Browser. Select your A Cappella and load it into Edison by Right Click>Edit...If you already know the tempo of your A cappella move on to the next step now. After the A cappella is loaded into Edison press the Play button. Next, move your cursor over the BPM Meter and Right Click>Tap... This brings up the Tap BPM tool. Begin to click on the faucet icon in time with the A cappella. The more times you click the more accurate your final BPM measurement will be. It may take multiple clicks to get the right tempo, but when the number doesn't change for 5-10 clicks or so, you know that you have the correct tempo.My sample looks like it is at 100 BPM. It is important to note that unless you want to change the tempo of your song to that of your A cappella, do not click the Accept button. Doing so will change your BPM to the number that you just tapped out. Hit the 'X' button in the corner instead.
Click image for larger version. 

Name:	2-2.jpg 
Views:	17 
Size:	93.4 KB 
ID:	47

2.2) Programming the Tempo of your A cappella
Move your cursor over the gray bar behind the name of the file in Edison and Right Click. Using the BPM value we just calculated (or if you knew it already), enter that value into the Tempo (BPM) box, then click the Accept Button. The number you just entered should now appear in the Tempo Readout. Save your A cappella (overwrite the old, non-BPM'd file) and close Edison.
Click image for larger version. 

Name:	2-3.jpg 
Views:	13 
Size:	84.1 KB 
ID:	48
What did we just do? We embedded tempo data into the Acapella itself for use later on with FL Studio's tempo syncing features. Why did we do it manualy and not with the Autodetect feature we noticed in the previous screen? In my experience, 99% of the time tempo autodetection gets it wrong, sometimes just by one beat per minute. If our tempo is even off by that much, however, this method won't work properly. So as tedious as it is to find the tempo manually, just do it.

2.3) Syncing the A cappella to your Beat
Load your newly BPM'd A cappella into the Step Sequencer, and then paste it into your Playlist. Once the A cappella is pasted in the playlist open the Channel settings by clicking on the A cappella in the Step Sequencer. In the Time stretching section, under the drop-down menu, you have a few choices. The ones that we are most concerned with are Resample and Pro default. When your A cappella is instructed to Fit to tempo, the Resample option will fit the tempo of the A cappella to that of your song by bending the pitch of the A cappella up or down, thereby speeding it up or slowing it down, respectively. The Pro default option will accomplish this task while maintaining the original pitch of the A cappella, and for this reason I most often use the Pro default option. Select Pro default from the drop-down menu and click Accept at the bottom of Channel settings. Finally, click on the icon in the upper left-hand corner of your pasted A cappella and select Fit to tempo.
Click image for larger version. 

Name:	2-4.jpg 
Views:	17 
Size:	65.4 KB 
ID:	49

2.4) Fine Tuning
Just because your A cappella is synced to your tempo doesn't mean it is synced to your beat. Zoom all of the way in on your Playlist and move your sample back and forth until it fits your beat. It helps with precision alignment to change the snap of your Playlist to 1/4 step.
Click image for larger version. 

Name:	2-5.jpg 
Views:	8 
Size:	6.8 KB 
ID:	50
Still having problems? Make sure that you calculated the original BPM of the A cappella correctly. If it is off by even 1 beat it will ruin everything!

---

Questions? Comments? Lost completely? Feel free to PM me. I'll get back to you as soon as I can.

Please Rep this tutorial if it helped ya! I put alot of effort into it.

---

Be sure to check out my other tutorials!