There are many ways to add vocal harmonies to your track. I sing mine and have a TCH harmony M pedal that I use or many times a combination of both.

This question comes up a lot so I'm copying a couple of posts that caught my eye here and hoping more of you will chime in with help for the newbies as well as any tips for us all.

From PgFantastic - Tips on using Melodyne

To use Melodyne for harmony,

1. open your original vocal track in Melodyne then copy to two separate tracks. TIP: about melodyne and correcting pitch, do not do it unless the vocal is extremely out of pitch and Never do 100% pitch correction, I would never use more than say 25% and that is probably too much. The reason is the human voice does subtle slides and trills through out a vocal performance and no matter how good a software is and Melodyne is a fine software it cannot keep up with the human voice. So what happens is you get parts that sound robotic when played against the mix. (AS A TEST: Put a vocal in melodyne correct the pitch and drift 100%, then put it back in your mix, and what sounded good against the mix originally will have places that are off key with the mix sharp and flat, which sounds crazy when the vocal is suppose to be set to perfect pitch.) I suggest instead of using correct pitch go through and the notes that seem out of pitch use the trill or slide function, this usually makes the note fall to the correct pitch for the rest of the song. If you use 100% pitch correction you will have some portions of the track that sound robotic and very unnatural unless the singer was nearly spot on perfect with their vocal and this is humanly impossible to do, not even the best singers can be in perfect pitch all of the time, just because of the way our voices slide and trill, the slightest change in air intake will change timbre and pitch, there will always be off notes, but against the mix they will fit because it is happening so fast, that it sounds like the singer is on pitch to the human ear.

2. On one of the copies delete all of the parts except what you want to use for a harmony part. Once you have done that;

3. hit select all, then drag all notes up the number of tones you want, I generally go with 3 up and 1 down for the harmonies as that sounds the most natural to me, you can however go 1 octave up and 1 octave down etc, use what is best for your application. on the copy track you have been working on, and I am sure if you work long enough you can make any harmony sound good.

4. Now go to quantize; this will make the harmony part sing off of the original which is what you want. Use the original track as the one to quantize to (the reason you use the orignal is because when you put these harmonies in your Daw the original is what you are harmonizing with.) Use whatever quantize you choose. I stay as close to the original as possible. 1/32 to 1/8 , but use whatever sounds best to you, this means melodyne will move the notes up and back throughout the notes the selected amount. Then mute the 2nd copy and play this harmony with the original and you will hear the harmony against the original.

5. Next use the formant tool to change the formant of the copy you are listening to in any places where the harmony sounds unnatural with the original. There is also a place to randomly offset timing, this is different than quantize because unlike quantize where for example if you set it for 1/8 off it moves the track either up or back 1/8. As you know harmony is not always that precise so the random offset will make the harmony more realistic sounding with the original part, still make sure to use the quantize first. The goal is to get the copy off of the original slightly forward and back so you don't have an exact replica but no so much that it sounds unnatural to listen to, also if the two tracks are exact it will sound muddy. I recommend also going through and choosing each note of the harmony part and setting the notes to either trill or slide, it takes a little time but is well worth it as the harmony part will sound more natural.

6. Use this same procedure for the second harmony, but if you went 3 tones up with 1st harmony go 1 tone down or more with this one, when going down though be very careful as this can get unnatural sounding very quickly and can cause muddiness in the mix.

I hope this helps!

Floyd Jane On Getting A Choir Sound

Since Josie asked "how did you get the choir sound?" - I thought a brief
description might be helpful to someone....

The "Choir" is nothing more than me singing a couple of times and then
processing that in RB using the TC Helicon plugin (provided by PGMusic!).
I loaded Robert's song in a DAW and sang along with it twice.
Once normally and once in a falsetto - both times, the same melody
that Robert sang (no harmonies).
I loaded Robert SGU file into RB and then loaded the 1st vocal I had done.
And then processed that with the Audio Harmony plugin.
Choosing "1 down, 3 up", selecting the Gospel setting under each voice,
and "medium choir" at the bottom.
That generated 12 harmonies. I saved each of those to a folder - using the mpg
option and allowing it to default to what comes up - a very low resolution.
(figured with a bunch of voices, the quality would not matter and it would save some space -
and to use any other resolution that many times is a pain,
because it returns to the low res every time)
I then did the same with the falsetto track.
Loaded all those (24 generated voices along with my originals)
in the DAW panned them all over the place, added a reverb to
the master out and....
Viola! Choir!

I mixed all those voices to one track ("the choir") to mix with Robert's
original track rather than have to work with them individually.