Playing intervals and chords from the C position
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 actual interval counts. Learning to recognize certain interval counts is a valuable skill in learning to play intervals sequentially as well as in 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. Of course, playing on this keyboard would be even more of a challenge for those with small hands. But with the keyboard we have, it's necessary to pay attention to the fact that there are two rows of keys and that both must be included in counting intervals. Secondly, those pesky gaps in the row of black keys means that the "pattern" for a given interval looks different depending on whether you cross one of the gaps.
Here you see the C position notes on the keyboard with the interval numbers between notes successive. The interval from C to D is 2 by counting the black key in between and D. There is no black key between E and F (the gap) and so the interval count between them is 1.
To get yourself oriented to the notes played from the C position, go to the piano and play the five notes while looking at the keyboard (for now). Just play up and down this reduced scale while building a mental image of the keys. Pay attention to where the black keys are even though you're not playing them. Most of all, focus on the gap where there is no black key between two white keys. Then think about how this affects the interval counts as shown in the previous figure. From now on, try to use these mental images when looking at the sheet music staff and try to avoid looking at the keyboard except to set the initial position.
intervals of 1
The entire 7 note scale of C Major has only two intervals of length 1 corresponding to the two gaps in the black keys. The C position notes include only the one case of a single interval between successive notes, E to F as seen above. On the sheet music staff, these notes overlap by 50% vertically.
Now go the to piano and play these two notes at the same time as a chord. Doesn't sound so great, does it? In fact, this is true for any two adjacent keys (inclusive of all black and white keys). 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.
All of the remaining intervals can be played sequentially or they can be played simultaneously as a chord. For brevity sake, the following descriptions will focus on playing them as chords, but of course the intervals can also be played sequentially (and the notes on the staff would then also be serial).
intervals of 2 (Major 2nd)
When you play the "Ode to Joy" snippet, you're playing intervals of 1 (between E and F) and 2 (all the others) as you climb up and down the scale. And it's easy to play because playing the next note is always just involves using the next finger over thereby pressing the next key over, either up or down. From the C position, there are only three possibilities for intervals of 2 as shown at right. None of the three cross the E-F gap. Playing summary:
playing fingers: adjacent
white keys in between playing fingers: none
noteheads: overlap 50%
Here they are on the keyboard in three successive octaves (with the A and B keys blotted out):
Each chord is played with adjacent fingers on adjacent white keys with a black key in between.
intervals of 3 (minor 3rd) and 4 (Major 3rd)
These two interval counts are discussed together because their appearance on the sheet music is the same. How is this possible? Blame it on the gaps. In the figure, the first two chords cross the E to F gap (remember that notes on the line are above the gap). So the interval count is 3.
Here they are on the keyboard:
playing fingers separated by: 1 finger
white keys in between playing fingers: 1
The third chord does not cross the gap so you have an interval total of 4. Finger-wise, play this chord just like the previous two, but now there will be an additional black key in between.
intervals of 5 (Perfect 4th)
There are two possibilities for an interval count of five. Both cross the E-F gap. Becaues of its pleasing sound, this is called a Perfect 4th instead of a Major 4th.
playing fingers separated by: 2 fingers
white keys in between playing fingers: 2
notehead separation: 1/2 of a notehead
intervals of 6
There are only 2 of these in the entire C Major scale, F to B, and B to F, neither of which are in the range of C to G. When played as a chord, this interval is infamously known for its dissonance, or unpleasant sound. But try them yourself and you decide. In any case, for most of the tunes you will encounter as a beginner, you're probably going to see it only played in sequence and not as a two note chord (however you will soon see these in three note chords and they don't sound so bad). So end of discussion of it for now. Let's move on to one more important interval.
interval of 7 (Perfect 5th)
There is only one interval of 7 and it spans from the lowest to the highest note in the C position range, C and G. So you'll play this chord with your thumb and pinky, with three fingers and three white keys in between. The sound of this chord has historically been regarded as so pleasing, it is called a perfect fifth (instead of a Major 5th).Playing summary:
playing fingers separated by: 3 fingers
white keys in between playing fingers: 3
notehead separation: full notehead
So one trend you may have noticed, is that all the chords with an odd interval count cross the gap. Looking back at the first figure above, you see that at the gap the interval count between the notes is 1 while it's 2 elsewhere. This explains the "odd" phenomenon. The take away message though is to be able to look at the relationship between the two noteheads and visualize how they translate to fingers on the keyboard.
The summary below shows of all of the C position chords on the staff (interval counts at the bottom). There are no octave numbers, so take this summary to the keyboard (it's on the Downloads page) and pick any octave you like. Practice recognizing and playing the chords without looking at the keyboard. With your right hand, position your thumb on a C key and play the chords using the corresponding fingers to play the other notes D through G. Use all five digits and don't move your wrist left or right. Next, repeat the exercise with the left hand. In this case, the pinky finger will be on a C key and the thumb on a G.
Unlike your computer keyboard where your hands remain in their "home" positions, on the piano you will not be able to play all of the notes on the keyboard without moving your hands left and right. This also means that the fingering plan will be customized to each tune you play. Thus the same key may be played with different fingers even in the same tune. Therefore, again unlike the computer keyboard, there is no permanent mapping of fingers to notes.