In music, vocals can vary from spoken word, singing, rapping, adlibs, harmonies, melodies or simply vocal chops/stuttering effects.
There are many ways to use a vocal sample or acapella in digital music production given the tools available in most DAWs. You have the option to pitch bend, stretch/warp and even manipulate sampling algorithms to preserve specific information when taking a sample out of its original context.
Sometimes, music can be composed of primarily vocals that dub as instrumentation too, for instance, harmonizing and adlibs. These types of vocals aren’t necessarily sung words just pitching of the voice itself. If you have a good ear for pitch and harmonizing, recording your own adlibs can be a valuable tool in your kit, especially after a little practice. Even if you don't have have the best voice, harmonizing a single pitch, using slight pitch correction tools and applying reverb is an effective method of masking small pitch imperfections in adlibs.
I challenge you to experiment with your own voice by creating adlibs! Here's a quick reminder how to get set up:
Step 1: set input device in preferences menu to desired microphone
Step 2: set IO on audio track to desired microphone input
Step 3: increase audio track send level to reverb for effect
Step 4: arm audio track
Step 5: record
Vocal chops, stuttering and fillins are more of a rhythmic enhancement using the voice rather than an assistant to a harmony or melody albeit they are, of course, still tuned to the scale of the project.
Spoken word comes in many forms. Often you will hear an excerpt from a famous, historic speech during an intro or theme section perfectly timed so the “punch line” of the speech falls directly before a main section or chorus.
As far as singing and rapping, not only do they become the centre of the mix driving the melody against an instrumental but they are an assistant to rhythm and subject to harmonizing with the current progression.
In digital music production, auto tune will only get you so far, especially if the vocals are designed to be the spotlight of a mix. Clean, crisp and pitch perfect vocal performances will guarantee an easier mix than trying to process a poor recording with strictly the tools at hand.
This concept goes with many other aspects of the music production process such as the importance of sample selection setting you off on the right foot.
A wise engineer once told me, “you can’t polish a turd”. Blunt but to the point. That being said, if you aren’t a confident, talented vocalist, don’t try to make yourself sound like Beyonce in-the-box. Hire a singer, or a rapper and collaborate with vocalists!