Riff Deconstruction: Back in Black - AC/DC Video Lecture | Guitar: Become a Pro (English) - Music

today we are going to break down the
theory behind the classic ac/dc rock
riff back in black a song that I have
affection for because my alternative
grandmother used to use it to sing me to
sleep as a young boy but yeah basically
all right you don't know the riff which
come on I know you know this riff sounds
like this so the main question is what
key is this in we're going to talk about
this in a second because it kind of can
be a little confusing at times now I
think this is a master class in using
the E minor pentatonic scale right
position one now if you look at this the
the pentatonic in niobium open green
open Q open you hope you only three open
three okay now we can make that entire
first part of that riff with just these
notes from this position of the
pentatonic right so if we start because
these are all power chords right the way
the Angus plays it he doesn't play them
as major or minor chords he plays them
as power chords which if you know that
is just the 1 and the 5 right so like if
E is the first note of the chord power
board of e tu a so it starts off just
like that now you can get the octave in
it so I have an ease of B and another
gear but start off with E you can play
an E minor shape but he's not playing a
minor he's just hitting these first
three strings and then he goes to a DIA
now it may look like a D major shame but
he's not playing it like that he's
really just playing another power for
daddy and a d e f g a as a fifth of D
and idea it may look like he's playing a
major chord but he's not
and major third isn't in there he's
playing in a ABCDE and a and E then
another a right so the chords are all
coming you can actually see these scores
inside of the pentatonic shape here
right so the first chord is just like
that this open e you a Judy is play the
Pentax feel open three open Q open Q all
right and then he jumps to here and
again if we go through that shape again
[Music]
and then last one a okay so we can think
of it as just kind of taking little
pieces so they're super popular and easy
shape to kind of make these chords right
and then he does this little link which
is literally just backwards through the
pentatonic scale with a little bit of
vibrato I feel a lot of vibrato on that
one all right so that gives us the first
half of it now the second time around it
is the same chord there we go now it's a
couple different ways to play it
something you've laid up here but I kind
of like this way better so I'm kind of
getting one finger per fret on the
e-string
four five six seven going seven four
seven five seven six seven seven now
this is where it kind of becomes
interesting because these are all in the
e pentatonic scale but they kind of
provides some insight into which chords
are actually behind this like we said
these are the first ones the e power
chord an e5 chord you may see it written
down now is it major or is a minor it
really isn't the one you plays it but
there is an underlying major a minor
chord behind this and this little riff
gives us a little bit insight into what
that is if we think about the notes in
the trip we start with a B in and go to
a G sharp then a me to an A
the beach would be flattered HR and then
it'd be right now the tonal center of
this song is e right one way to kind of
find out what kiya song is in is it is
where is the resolution where would you
end this song if you had you for your
life kind of seems like it ends
fittingly on that II which will give
more to in a second but the fact that we
have this be known and the G note or did
you sharp note that tips me off that
we've got an E major thing going on here
if we just play the notes of the E major
chord we end up with an e a G sharp and
a a it's like an arpeggio of an E major
form alright so if we had to choose a
chord that sits behind this progression
I would be so presumptuous to say the E
major would be the court we would choose
you do the same thing for the D chord
and even though we're playing is a deep
our fourth if you had to pick a major
minor chord in there what would you pick
would you pick a minor chord or a big
major chord
I think you pick a major chord right and
then same thing for the a would you pick
a minor chord major right I think we can
all agree that that would be a major
chord so the major chords behind this of
course behind this wrist are going to be
e major D major to a minor and then E or
not I said a minor a major right so then
then you do it minor pentatonic lick
over right so what's going on here we
got minor pentatonic with major chords
well the sound of Blues is the minor
scale played over major chords right so
even though we have an E major chord but
it's kind of like our tonal Center if
you will we're using notes from that
really bluesy pentatonic scale so we're
playing E minor pentatonic over an E
major an E major and a major and that
kind of gives us that really bluesy
sound now if you watch some of the other
videos I did I'm like finding out what
key you're in you'll know that
diatonically like in the major scale
there are only three major chords and
three minor chords right so a good way
to find out what key you're in if you
take three major chords e b and a and
one of these is going to be the first
degree one is going to be before one is
going to be the five if you don't
understand what that means I will link
you in another video to kind of like
explain the one four and five better but
a dead giveaway when you find two major
chords together is that there's a four
in the five right so which two of these
chords are together G V and a V and E
are letters right next to each other so
V is the four e is the five and a is the
one all right so now if we think of it
that way we can think of E to D a as a
five four and one progression but the
interesting thing is when we think about
it that way if we were to resolve on the
one chord which is where song is usually
resolved it sounds like this
[Music]
there's no resolution there right so
let's go out because that tonal Center
is II it kind of leads you to believe
that E is in the key is it's in the key
of E right so a lot of people would say
the song is in the key of you and I'm
not really going to argue that to me how
I'm kind of perceiving it I think you
can make a better case that it's in E
mixolydian which would be the fifth mode
of a major so we're using the chords of
a major but it's so heavily e centric
that it's easy and of mode within a you
know you could say that I don't think
you would be wrong but the interesting
thing about that is if we take the note
of E mixolydian right like I always
think in shapes right so I would start
with the seventh fret on the a-string of
the ear and then I play that right there
you think of that flat seven being a d
right and that's kind of like a very
prominent note in this song thank you
here right so I kind of think it's an if
you mixolydian you could say it's an e
whatever I mean if you really get hung
up on like what keep our chord type
songs are in I think you probably have
different issues that you might need to
talk about again in the key of A and the
key V whatever it's in the key of
rock'n'roll is the real answer to what
key the song is in great risk
it uses an incredible amount of just
kind of power and I think a lot of that
stems from that minor pentatonic which
is a pentatonic shape so you know if you
want to kind of like incorporate this
and maybe like your own playing and
stuff like that just kind of mess around
and some kind of tonic shapes and try to
make pieces of chords out of them
because so much of this is like it
sounds like chords in a wreck but I
almost kind of think of it all is like
one in the same like the chords I think
are almost just as important part of the
risk as
the lick is so uh there you guys have
any questions please let me know and
also give me some suggestions on what
may be you want the next riff
deconstruction to be thanks a lot