INDEX
3rds & Thirds Part A Playing and Having Fun
3rds & Thirds Part B Some Theoretical Foundations
3rds & Thirds Part C The Concerpt of 3rds as Partial Chords
3rds & Thirds Part D The Ambiguous Nature of 3rds as Partial Chords
3rds & Thirds Part E 3rds as Partial maj7, min7 and dom7 Chords
3rds & Thirds Part F: FUN FUN FUN
3rds and Thirds Part A - Playing and Having Fun
In April 2020 @DavidP composed, recorded and shared an instrumental track in which he used double-stop 3rds as the melodic basis for his guitar track. Stream Voices Of Vincent Blue Beast by David Preece | Listen online for free on SoundCloud
In turn, I was inspired to create this article exploring the concept of 3rds on the guitar.
I will lead the exploration with reference to intervals, scales, chord shapes, the CAGED system, triads and more. But first, I think that you should all have a little fun playing around with some 3rds. They are very accessible and user-friendly from the outset. As soon as you have a few very basic shapes under your fingers you can begin exploring and making music. So … here goes with the fun from the get-go.
DavidP played his 3rds on the B & E strings in the key of D. I propose we start from the same place.
For these and all other 3rds we will look at the shapes no higher than fret 15. The shapes do repeat once you reach the octave.
TAB for the shapes on the B & E strings.
There are only two shapes. Take a few minutes to play these ascending and descending the neck. As you do so, consciously listen to the sounds. Then begin exploring and having fun. They are in the key of D so I recommend you play a drone note or a simple, occasional bass note on the open D string. To begin with you may simply want to slide up and down. Something like this.
Double Stop 3rds in the key of D on the B & E strings
Tab for the mp3 sample:
Once you get a feel for using these 3rds you may want to vary how you play them. They do not have to be played as double stops (both notes simultaneously). You can arpeggiate them.
Arpeggiated 3rds in the key of D on the B & E strings
TAB for the mp3 sound sample:
Now go have some fun and explore, play, enjoy. 
Then come back for more juicy goodness.
Excellent post @Richard_close2u. I’m going to bookmark this for when I’m competent to look at it properly. Thanks.
Good that this one is coming to the attention again, for a few weeks I often click on the other BT and play the 3 rds & thirds for fifteen minutes in a row, it really helps to get a better and faster understanding of the 5 patterns and more on a different level,(for me anyway)
Thanks…And also David for the music of course
It was an unexpected and added bonus when Richard was inspired to share this exposition with us after listening to my efforts, but the credit and thanks are really all for Richard.
Be modest if you like, but your inspiration has brought about a nice exercise (expertly presented I might add) by Richard, and will hopefully inspire many fellow students.
Hopefully you are finding that simply playing these 3rds is a whole lot of fun. The enjoyment factor can be ramped up further if you magically have a band playing alongside you while you explore and play.
Click play on this one and get your fingers moving.
Go play.
Good to see this resurrected
I hope you’re exploring, enjoying and surprising yourselves with the ease of making great sounds from these tiny little pairs of notes we call 3rds.
@DavidP certainly had fun …
Here is a TAB and mp3 of my transcription of his guitar part in his track. (David kindly gave permission to share this)
Voices of Vincent Blue Beast - guitar part transcribed in Guitar Pro as an MP3 audio file.
You should by now have picked up your guitar and learned those two shapes on the B & E strings, moved up and down the fretboard and made some music. Have you played over the backing track yet for more pleasure?
You have! Excellent. Wow. Isn’t that just a whole lot of fun and so, so musical.
And you’ve only been playing little note pairings on the thinnest two strings.
The fun doesn’t stop there.
These 3rds can be found on other sets of two adjacent strings. So your enjoyment can expand.
Next we will learn the shapes for 3rds on the G & B strings. Go steady though … the shapes are not the same as those you have just learned. There are still only two shapes in total on the G & B strings so learning them is not too challenging. Just ensure you get your fingers working right. And once you have them under your fingers you’re good to go.
Here is a TAB for the shapes on the G & B strings.
Take these shapes and spend time playing them as before – moving them around, ascending and descending the neck. As before, listen to the sounds. Then begin exploring and having fun. Again you can play a drone note or a simple bass pattern on the open D string. And, of course, once comfortable, play with them to a backing track.
To begin with you may simply want to slide up and down … something like this demo.
Double Stop 3rds in the key of D on the G & B strings
TAB for the mp3 sample:
As before, you do not need to play these 3rds as double stops.
Arpeggiated 3rds in the key of D on the G & B strings
TAB for the mp3 sample:
Far more fun than Harmonic Minors. 
Brain’s a bit fuzzy from when this was last covered but the double stops are R/3 or R/b3 in respect of the Key diatonic chords ? That’s what I am seeing from an interval shape perspective but its been a long day.
@TheMadman_tobyjenner Fun indeed Toby. Thanks, as so often, for checking in and playing along. There is some explanatory stuff over the horizon for sure. Majors & Minors? Could be.
Looking forward to it, as I’d carried this over in my schedule from the old post. 
Next comes 3rds on the D & G strings. Within the key of D this throws up a small issue that you will be fingering the D string meaning it won’t be possible to have it ringing out as a drone so much. But you can still play with the open D string and these 3rds.
Here is the TAB for the shapes we need.
Hang on … they look very familiar.
The same shapes as on the B & E strings but in different positions on the fretboard.
Mmh. That’s interesting.
As before …
Double Stop 3rds in the key of D on the D & G strings
Tab for the mp3 sample:
