D major with no C tone

Question

I just played the melody of the famous German Epiphany song "Stern über Bethlehem" and thought it was g major. When I googled the melody, I saw it written in d major. I was confused but then saw that there is no C in the melody at all.

So I wondered: How can I spot it from the melody? It is because it starts and ends with a d? Or are there other reasons?

Answer 1

Great question! For the task "figure out what key this melody is in," there's no one simple, foolproof way. Instead, we can add up a lot of clues to come to some degree of certainty.

First, if we're being really picky or pugnacious, we could argue that melodies aren't "in keys" at all. The linked sheet music also has chord names printed above the melody; it's been "harmonized." These chords are much more powerful than melody alone at establishing a key. But it would be possible to harmonize a given melody with different choices of chords, perhaps even some that create a different key. It's often easy to use the relative minor; I could harmonize this melody in such a way as to make it be in B minor rather than D major. (Many techno remixes use this trick to take a new angle on the original song.) It would definitely be possible to imagine an ambiguous melody, that might suggest more than one key.

But in general, with most tonal melodies, there is an easy, reasonable, "first choice" for key. There are a lot of clues toward this decision. No one of these clues is foolproof; one can find exceptions. But taken together, they can add up to a conclusion.

• Key signature. If the composer has included a key signature, this ought to tell us what key they think it is. The first problem here is that it doesn't tell us major vs minor mode. A key signature of two sharps could be D major or B minor. And if the piece is in a more unusual mode, things might get tricky. If it's in D-based Mixolydian mode, they might choose the two-sharp signature and just put natural signs on all their Cs, or they might use a one-sharp key signature. And inexperienced composers might make misleading choices or omit a signature altogether. Also, in complex pieces, smaller sections might be in a different key, without bother to change the key signature for that portion. But in general, this can be the first clue.
• Last note. For most simple, tonal melodies, the last note is the tonic. There are exceptions: The Christmas tune "The First Noël" ends (and starts) on the third scale degree. And if we're looking at a "harmony part," the last note will likely be another member of the tonic chord (like scale degrees 3 or 5). But as a simple rule of thumb, most melodies end on 1.
• First note. This is less consistent. It's much easier to find tunes that start on a scale degree other than 1 than to find ones that end on them. But still, if the starting note is the same as the ending note, and matches the key signature, this is another clue. If the melody has a "pickup" or "anacrusis"—a few extra notes before the first full measure—then it can be helpful to ignore these and look at the first note of the first full measure, the "downbeat." (See the later point about "metrically strong placement.") This still isn't foolproof, though; the familiar "happy birthday song" has a pickup of scale degree 5 and a downbeat of scale degree 6.
• Most prevalent note. In "Stern über Bethlehem," there are 13 D notes (counting ties as a single note). In contrast, there are only 9 Bs, and even fewer of other pitches. This is also not a foolproof clue; out of the first 25 notes of "The First Noël," only 4 are the tonic. But it's another rule of thumb.
• Placement of the note on metrically strong moments. The second-most frequent note in this tune seems to be B. But in the first measure, it falls on beat 4, the weak beat of the measure. In the next measure, it's not even on a beat at all, but on an "and," falling in between beats. In contrast, D falls on the downbeat—the strongest beat—in six out of the total eight measures. We do have a very metrically strong B in the 5th measure, falling on the downbeat and in fact dominating the first half of the measure. But this seems to be outweighed by all those metrically strong Ds. (This is why we can still hear which note is the tonic of "The First Noël," even though it starts and ends on ^3, and has few instances of ^1. In the first 25 notes, those four instances of the tonic pitch are all on downbeats. In fact, if I write it in the meter of 6/8, they are all of the downbeats!)
• Accommodation of cadences. If we take the position that "being in a key" means having harmony, then chords will be implied, whether we write them down or not. And in conventional tonal practice, these follow some common patterns. The most "important" chord is the tonic (the "I chord"); in the key of D major, a D major chord. The second most important is the dominant ("V"): If I play a melody consisting of only two notes, A - D, you will probably imagine it as a cadence from dominant to tonic. We get this motion, A chord to D chord, three times in the harmonization shown, as we go from the end of each line to the start of the next. The very last few moments are the most important, as this is when the harmonic motion "comes home," and "cadences," usually with that dominant-tonic motion. We don't see A as the next-to-last chord—but we get G, which is another very common cadence, IV-I (especially in hymn-type music). Even given the melody alone, before anyone added the chord symbols, the melody implied these cadential motions, as the lines ended in notes like E or A, which suggest that dominant A-major chord.

With time and practice, all these clues will become intuitive and you'll find yourself just saying "Well, it feels like it's in D major," but it will be signals like these that add up to this feeling.

Answer 2

The melody isn't in a key

In this particular case, it's a bit tricky to spot the key, because, strictly speaking, the song isn't "in a key".

The melody is built around a pentatonic scale: D - E - F# - A - B. That makes it sound major-ish, but it lacks a key element — the "leading tone", C#. The movement between the seventh and eighth (first) degrees of a major scale are one of the principal characteristics of major (and minor, when the seventh degree is raised to form a leading tone). Nevertheless, it's conventional to use the D major key signature for a D pentatonic melody. One of the functions of the harmonization is to add the leading tone via the A chords, making the song D major.

See also: Wikipedia

Alfred Zoller chose the pentatonic scale as the melodic material. (translated from German via Google).

How to hear D as the pitch center

For this melody, one's ear needs to notice how the tue revolves around D in the first, second, and fourth lines. Each begins on D and returns to D, importantly at the beginning of each measure, the most metrically significant beats (i.e., most emphasized).

The case against G

To make the case against G, one notes that the melody never proceeds from F# to G, which would be a primary, characteristic element of G major.

Answer 3

I really like this song, too. I have seen it in many different keys (presumably in the major keys of D, Eb, E, F). This song is also well suited for doing some improvisation around the melody. There are in fact songs were it is hard to determine the key, especially when church modes ("Kirchentonarten") are used. I think in this case it is clear. The referenced sheet music contains chord labels. The last chord is D and the key signature consists of two sharps. Additionally, all the used chords contain tones of the D major scale, for example there is an A major chord (with C#) and no A minor chord (with C). If you play the chord progression, you will feel "at home" when you hear the last D major chord because it is the tonic. By the way, the first chord in bar 5 seems a little bit too "jazzy" for me. With the melody it becomes a D6. I would rather prefer a G major or B minor chord (in German "Hm") because it better fits to the melody. But harmonization is a matter of taste I think. And taste is debatable.