Non-diatonic chords add a lot of excitement to traditional music by creating a mix of feelings and making songs more interesting. Here’s how these unique chords work with common music patterns:

1. Tension and Resolution: Non-diatonic chords create a feeling of tension. This tension wants to be resolved, usually by moving to diatonic chords. For instance, if you play a flat VI chord (like Bb in the key of C major), it often leads to a strong resolution to the V chord (G major). This setup creates a feeling of wanting to go home.

2. Common Non-Diatonic Chords:

   • Modal Interchange: This means borrowing chords from a related scale, like using the bVII chord from C Mixolydian while playing in C major.
   • Secondary Dominants: These are special chords that point to other diatonic chords, not just the main one. For example, D7 can lead to D minor, which adds an interesting twist.

3. Statistical Impact: Research shows that about 30% of popular songs use at least one non-diatonic chord. This can really add richness to the music.

4. Cadential Functions: Non-diatonic chords can do certain important jobs in music endings:

   • The deceptive cadence (like V-vi) often includes a non-diatonic chord, such as using vi from another key.
   • Authentic cadences can also use secondary dominants, like D7 in C major leading to G.

Using non-diatonic chords not only keeps the traditional feel but also brings in new ideas. This combination helps create rich and engaging music that captures people's attention!