How to determine what key changes are appropriate?

Question

In the month or so until my band get back together I've been working on writing some new material, and want to try and expand how complex my songs are. I apologise if there are a lot of questions - I'll gladly split them up if needs be. Say I've got a nice little riff/idea in D minor. I'm happy that the relative major of that is F major, how modes fit into a major/natural minor scale, the tonality of the various degrees of the scale, and the concept of the circle of fifths. I also appreciate that a song need not necessarily change key to have a very different sound.I'm looking at complete changes of key to try and bring a new direction to a song outside of these ideas. So ultimately, can someone explain: - What keys can I change to from a given key? - What is the theory behind the potential key change? - The word modulation seems to by used a lot in similar circumstances. What is the difference between a key change and a modulation?The more detail the better, as I want to understand the theory behind what I'm doing for myself rather than just follow rules blindly.

Answer 1

Hello! how are you today? I hope you are safe at home!

You ask some interesting questions here! It is a pleasure to answer them since I notice that you are just working hard to give shape and direction to your compositions!

Modes and major / minor music: The natural major scale and the minor scale are, in fact, modes! The major scale is the Ionian Mode (based on the I degree) and the natural minor scale is the Aeolian mode (based on the VI degree)… they are two of the seven modes that the Natural Major Scale can generates. The minor scale actually comes from the 6th grade of the major scale. (As an example, you can play all the white keys from A to the next A on a piano and the interval structure that you will get will be the one of the minor scale).

Circle of Fifths: In modern songwriting, it will be much more useful to use the Circle of FOURTHS (which is the inverted circle of fifths) to help you create harmonic progressions.

The Cycle of Fourths is C - F - Bb - Eb - Ab - Db - Gb - B - E - A - D - G… .C.

If you play several chords belonging to the same scale, consecutively, and those chords have their root in consecutive notes of the circle of fourths, you will already be making a useful harmonic progression. Of course, after this hundreds of composing resources begin, but as a start it is important to understand this topic.

Changing keys to achieve a different sound: Not necessary. In fact, the key change is getting a little obsolete in these years. Rather I would recommend you to study a bit the modal music (composition based on modes) and the modal interchange (use of some chords belonging to a scale different from the original scale of the song).

When to use key changes: we must remember that singers have a limited vocal range. Likewise, it is considered unmusical that a given harmonic or melodic motif varies at intervals greater than a major third (it really sounds strange that a song passes, for example, from C to G). This was not uncommon in classical music but it’s not typical nowadays.

In modal music and music that uses modal interchanges, you have several intensity and color options to give your songs. For example, the major natural scale has 7 notes, which generate 3 major modes, 3 minor modes, and 1 diminished mode. These interval structures (modal scales) can be used in various ways. For example, if you want to play a song in minor mode with a slightly more nostalgic or longing color, you can “clone” the interval structure that is generated from D to the next D (Dorian Mode) and apply that “mold” to the root of your song. (For example, listen to R.E.M.'s “Losing My Religion” or Sabrina Claudio's “Unravel Me”). These are songs in Dorian Mode… that is, they use the same interval structure on a smaller scale except for the 6th grade (they use a major 6th).

If you are interested in learning a little more about contemporary harmony and its applications, we might have a course or a few lessons! My courses include nice interactive and PDF materials that I make for each student according to the topics we are studying.

Have a happy weekend and keep working! You’re doing great getting interested of all this!

Carlos