It had already been mentioned how to use modal interchange to achieve melodic contrasts in a composition. However, the story doesn’t end there, as we can also achieve harmonic contrasts by replacing a major chord with a minor one that is also distant from the key in question.

This is accomplished by using chords that are not part of the key but fulfill the same function of tonic, subdominant, and dominant. The following table shows chord options that can replace the ones listed there.

For example, a C, F, C, G7 progression can be turned into C, Ab, C, Db7. In this case, the Db7 chord does not appear in the table, but it is the tritone substitute for G7. What must always be taken into account is that the melody must be compatible—meaning that minor second clashes should not be generated in order to respect consonance.

An example can be heard at the 00:50 mark of the song “Sigo aquí” by Eslabón:

The author of these lines decided to use that same song and record a cover with Erica Lux, precisely changing the previously mentioned progression: C, F, C, G7 changes to C, Ab, C, Db7. You can listen to the recording at the 00:54 mark below.

This is just a small example using a Pop song; the reader is invited to try making this change in different musical contexts. It can be done in traditional songs, as long as we make sure that the melody allows it.