This is my 3rd Lesson on ultimateguitar and to be really honest I'm not that good on this topic, I've only been playing for a year and this lesson might not work for you but I'm gonna try my best to make a good one.
Lets cut to the chase, if you've ever heard of bands like Iron Maiden, Metallica and Children of Bodom, you'll notice that when they play live one guitarist is playing a melody somewhere down the fretboard while the other one plays it somewhere completely different but they still manage to make a balanced and you would think that they're playing the same notes.
In this lesson I will cover the theory behind melodies and harmonizing them and hopefully you will come up with some ideas on how to create harmonies for some previous riffs you might have made.
P.S. - You should know a little bit of theory to be able to understand this lesson, if not then I strongly suggest you go learn some otherwise this lesson will not make any sense to you.
Anyway on to the topic, now.. a melody is just a sequence of notes sometimes reffered to as a 'voice' and the harmony is the second voice being played on top of your first voice.
Now there are two ways of approaching this. Your second voice can be a higher voice (higher pitched) or lower voiced (lower pitched) depending on how you want to harmonize it. People usually harmonize with thirds or fifths which are essentially power chord. Lets take a bunch of notes, in this case we'll use the key of E minor for example, and you're playing the notes E F# and G, if you want to harmonize these using thirds you will play G A B on top of the first melody. G is a minor third away for E, A is a minor third as well and B is a major third. The reason why we're playing these notes is because we want to play the notes that are in the key of E minor. It is up to you to decide if you should play a minor or major third but you want to stay in key.
Let me show you a quick example in TAB form, here is your first melody:
e|------------
B|------------
G|------------
D|------------
A|--7--9--10--
E|------------
The notes are E F# G respectively, now if you're harmonizing with thirds, you will play this:
e|-----------
B|-----------
G|-----------
D|--5--7--9--
A|-----------
E|-----------
So this is when you're playing a double guitar harmony. You can add another guitar to make a triple guitar harmony... now this may sound really awesome and everything but you will encounter some problems. One is that there aren't many bands that do that so you will be seen as an outcast lol kidding.. um.. a problem that you will come across is of sound clarity. The notes might sound muddy and messed up because there are too many guitars mixing in different harmonies.
And for this example that I just showed you the third guitarist will most probably play in fifths and the fifth of F# is C#, but C# is not in the key of E minor. But there are ways of getting around this, either you could harmonize with something else like octaves, but that might sound a bit messy, or you could change the C# back to the natural C note but C isn't F#'s fifth. So you have a bit of a problem there. It might sound a little strange when you harmonize it that way.
Anyway, once you get the hang of harmonizing then by experience you will come across ways to solve this problem, besides you probably aren't even going to use 3 guitars heh.
Musicians also harmonize when playing power chords or triads of any kind, for example if you're playing an E minor power chord then you can play a G minor over that if you're harmonizing using thirds
Example:
e|-----|-------
B|-----|-------
G|-----|-------
D|--5--|--1----
A|--7--|--3----
E|-----|-------
I'll leave you with one last example, this is from the song 'Phantom of the Opera' by Iron Maiden. This riff comes somewhere in the middle before the solo:
Guitar 1 Adrian Smith (Lower Voice)
|--------------------------------------------------------7--------|
|--------------------------8------8p-7--8~---7h-8p-7--8-----8~----|
|--9p-7--9~----7h-9p-7--9-----9~----------------------------------|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
|--8p-7--8~---7h-8p-7--8--7------------------8--7-----10--8--7----|
|----------------------------9~---9p-7-9--7--------9------------9-|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
Guitar 2 Dave Murray (Higher Voice)
|-----------------------------------------------------------------|
|------------------------10------------------------------15-------|
|-12p11-12~-11h12p11--12-----12~--16p14-16~--14h16p14-16----16~---|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
|-----------------------------------------------------------------|
|-------------------------------------------------------------------|
|----------------------------------------------12-10----13-12-10----|
|--16p14-16~-14h16p14-16-14--12~--12p11-12~-11-------12----------12-|
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
|-------------------------------------------------------------------|
Hopefully you have gained something from this lesson, I do apologize if I haven't explained it properly but I've tried my best to. Cheers guys, keep rockin'!
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