playing chords in any scale
Of course, you've already been playing intervals in every music snippet so far. There's an interval between every successive note by definition. However, you probably haven't paid any attention to the interval counts between them. Learning to recognize certain interval counts is a valuable skill in learning to play intervals sequentially as well as chords.
If the keyboard keys were all the same width and lined up without recessing the black keys, it would be pretty easy to learn to recognize and play a given interval because that physical distance would always be the same everywhere on the keyboard. But with the keyboard we have, not only is the distance not fixed, even the direction may change. Direction meaning shifting from white to black key rows or vice-versa. It's a bit like the chess pieces castle and rook. The castle always goes in a straight line while the rook starts off in one direction and then goes off to the side.
What further complicates matters is that sometimes the direction can be different depending upon whether the interval crosses one of the black key gaps. So for example an interval of four, the movement is like a castle from and to keys with the same color on the same row if there's no gap. But if there is, then the movement is like a rook, changing between white and black key rows. (insert figures)
You may rightfully ask, why do I need to know all this if I'm only going to be playing in C Major scale which only uses the white keys? The answer is that a bit of understanding of how this works is a worthwhile investment in your music playing future. If you stick to it, you will be playing on the black keys and this explanation will hopefully make it easier.
So what is the message? The message is that playing an interval either sequentially or as part of a chord requires the ability to adjust the distance and direction depending on whether a gap is crossed or not. So one playing approach the for C Major scale is just to memorize all of 2- and 3-note chords without thinking about intervals. That's not so bad. But later when you start playing in other scales that include the black keys, you will have to memorize all of the chords in each of them, and they're not going to be the same. So yes, you can memorize each new chord as you learn it, or if you learn the rules, you can figure out and play any chord in any scale. Probably not real-time for awhile, but with practice.
One of the goals of this course, is to help you to rely less on memorization by understanding how things work. The alternative to total memorization is to be able to see intervals on the keyboard and on the sheet music. Then you don't even think about scales, you just, uh, play what you see.
visualization of 2-note chords
intervals of 1
It's easy to see an interval of 1 anywhere on the keyboard, even when crossing a gap. It's just the next key up. In WYSIWYP, it is easy to see since the notes overlap by 50%. The figure shows sequentially all of the intervals of length 1, which is simple the full 12 note scale.
The C Major scale includes only the naturals and therefore there are only two cases of a single interval between successive note, B to C and E to F.
Now go the to piano and play any two sequential notes at the same time as a chord, such as B-C, E-F, or any other two adjacent keys. Doesn't sound so great, does it? This is why chords containing an interval of 1 interval don't really exist "normally". Net, no need to spend any more time thinking about intervals of 1 other than what they look like on sheet music when playing them sequentially.
intervals of 2
Even with intervals of 2, the visualization becomes a little more challenging due to the gaps.
The figure shows all of the possible 2 note chords in the full 12 note scale. Remember that crossing a gap occurs when the first note is below the line and the second is on or above the line. With a little study you can see that when that happens, the two notes are on different colored keys (remember that the circles are the white keys, the triangles the black). That's only 4 times out of 12. Without crossing a gap, the two notes are on the same colored keys.
The C Major scale has no instances of a 2 note chord crossing a gap, but five where they do. Why is that? The short answer is that in order for a two note chord to cross a gap, one of the two has to be a black key. (See the long answer at the end of this lesson.) Take a few moments to look at the figure and visualize the associated keys of each of these five echords on the keyboard. Now go to the keyboard and play them. The nice thing about the C Major scale is that for each of the chords, the notes are adjacent on the white key row (the ones with the black key in between). The exceptions being B-C and E-F (no black key in between). Again, the thing to remember is how these chords look on the sheet music with their 50% overlap.
intervals of 3
In this case, the observations about what color keys are involved in a chord when crossing a gap are just the opposite from those of intervals of 2.
Here, these chords have keys of the same color and this happens six times. And four of those are in the C Major scale. The appearance of these on the sheet music is very clear, two circles stacked up. Take the time to play these on the piano while noting how they all cross a gap.
intervals of 4
Hopefully, you are already guessing about the flip in observations when crossing a gap in this case. And yes, they're as they were for intervals of 2. So odd numbers of intervals are the opposite of even numbers. So here are all of the intervals of 4:
And on the C Major scale here are the four chords available.