How to transition between chord progressions of two songs in different keys?

Question

I play mostly in a church band setup, focused around chords. Often they'll be an interlude between songs where someone might come and share a prayer or bible reading and I've noticed some people are able to transition smoothly from the key of one song to the key of the next whereas I just have to stop and wait until I recognise we're now in the new key.

How does one go about knowing how to do such transitions and making them as smooth as possible?

As an example we might be playing C - Am - G - F and change to a song using a similar-ish progression G - C - D - Em. We'd want to transition subtly over quite a few bars so people realise we're playing a new song without getting distracted. As a relative novice, a walk-through of this specific example would be really helpful rather than a theoretical answer (although explaining the why would be great).

Answer 1

There are many different ways to modulate from one key to another, and without hearing your specific group I have no way of knowing what they are doing. This is why I recommend you listen to what your group is doing, and try to learn to recognize the chords they are playing (presumably there is someone leading the group -- possibly just one of the other instrumentalists who everyone tacitly agrees to follow). Worst case, I'd recommend asking someone ahead of time what they're doing.

In my experience, most actual modulations occur rather quickly (within a few bars in Classical music, and often immediately in pop music, with no intermediate chords), so the "quite a few bars" that you are describing seems unusual. Until you get to atonalism (and you aren't) there's not really such a thing as "in between keys" (at least not for more than a chord or two) -- you're pretty much in either one or the other (or a different one).

What might be happening is that most of this section is either in the original key, with a modulation just before reaching the new key, or the modulation comes early on, and there's just some progressions in the new key. Another possibility is that they make multiple modulations to one or more intermediate keys in between, before arriving at the final key. If you want a longer chord progression, when in doubt, the circle of fifths always provides options for smooth chord progressions, by always going to the chord whose root is a fourth higher (or fifth lower) than your current one. Picking chords a third lower than the current chord also tends to give pleasing results. If possible, you may want to focus on using chords that exist in both keys (this isn't always possible, depending on what chords are in each key). Of course, you could always do weird stuff with augmented sixths, or diminished sevenths, but given the nature of the music, I very much doubt this is the case.

At some point, by the end of your chord progression -- and this is the most important part -- you're going to want to establish the new key by using a dominant/tonic progression (a cadence) in the new key. This means playing the V (or V7) chord followed by the I chord in the new key. This is possibly what you are noticing when suddenly realize that you are in the new key.

As you can see, there are really far too many options for me to provide you with a very useful answer. But since you ask for an example, here's an extremely simple way to transition between two chord progressions in different keys, using only a single new chord. I'm going to slightly "rotate" your first progression to something I think sounds a bit more natural, and then move into the second, modulating from C to G by using the dominant 7th of G, which is D7.

|: F - C - Am - G :| F - C - Am - D7 |: G - C - D - Em :|

Part of the logic here is that the original phrase ends on the dominant of the original key (G) so we just modify it to end on the dominant of the new key. Another helpful fact is that the preceding chord (Am) leads into the D chord really well, because D is a fourth above A (look at the circle of fifths: A -> D -> G is just moving around it) and because Am is a chord that exists in both C major and G major.

Answer 2

In your example, your focus should be entirely on the second key, not the first. This is because the purpose of the music is to lead a group of people in worship. Presumably everyone is playing/singing the first song correctly. So what you want is to provide a musical phrase that enables the singers to continue into a new song without losing track of the flow of music and the key. In other words, the transition to song 2 serves the same function as the intro you would have played for song 1.

Song 2 is in the key of G, so that is the critical focus. What chords will give the right notes for that key? The 2 clearest chords are G and D7. So here are some possible transitions:

(1) C - Am - G - F - D7 - G………

(2) C - Am - G - F - G………

(3) C - Am - G ………..

Examples 1 and 2 involve playing the full progression of song 1 and then beginning the song 2 progression. Example 3 is different, in that it plays just part of the song 1 progression and switches to song 2 by using the chord that is common to both songs.

These examples show that there are multiple possible approaches. So my final comment would be that this is not just an individual but a band issue. Even if you have your own answers for linking songs, it doesn't follow that your fellow band members would do it the same way. This needs rehearsal along with other elements of the worship event.

Answer 3

Print a copy of the Circle of Fifths from the internet and use it as a guide. You will probably discover through your own experimentation or by reading about it on-line, that it sounds better when you transition from one key to another if you don't jump more than two places on the circle from the key you are on. You can see from the circle of fifths that as long as you don't jump more than two keys, there will be some chords common to both keys. The circle of fifths will make it easy to visualize and find chords that are common to each key which will make good pivot chords to modulate from one key to the next.