# Composition Principles — Music Knowledge

> How to make musical decisions: melody, harmony, rhythm.

## The three foundations

### Melody
- Singable line
- Memorable shape
- Range appropriate for vocal type
- Relates to lyrical content

### Harmony
- Chord progression supports melody
- Common progressions: I-V-vi-IV, ii-V-I, I-IV-V
- Tension and release pattern
- Key signature defines mood (see key-signature-mood.md)

### Rhythm
- Tempo (BPM) sets energy
- Time signature defines feel
- Syncopation adds interest
- Drum pattern grounds song

## Common chord progressions

### Pop (I-V-vi-IV)
"Axis of Awesome" progression. Used in thousands of hits.
In C major: C-G-Am-F

### vi-IV-I-V (alternative)
Same chords, different starting point. Sadder feel.
In C major: Am-F-C-G

### I-vi-IV-V (50s progression)
Classic doo-wop. Nostalgic.
In C major: C-Am-F-G

### ii-V-I (jazz standard)
Foundation of jazz harmony.
In C major: Dm-G-C

### I-IV-V (blues / rock)
Three-chord rock and blues.
In C major: C-F-G

### Modal mixture
Borrowing chords from parallel modes for color.

## Form principles

### Repetition
Familiarity comforts. Audiences love hearing things again.

### Variation
Pure repetition bores. Vary slightly each return.

### Contrast
Bridge contrasts verse/chorus. New chord progression, key change, dynamics shift.

### Resolution
Most songs need to feel "resolved" at end.

## Composing process

1. **Lyrics first OR melody first** (either works)
2. **Establish mood** (key signature, tempo)
3. **Build chord progression** for verse and chorus
4. **Compose melody** that fits chords
5. **Refine rhythm** (syncopation, accents)
6. **Add bridge** (contrast)
7. **Arrange** (instrumentation per section)

## For AI music (Suno):

Specify in prompt:
- Tempo (BPM)
- Key signature
- Genre (which carries chord progression conventions)
- Mood
- Instrumental style

Example:
```
[Style: indie folk, 75 BPM, F minor, melancholic, acoustic guitar driven]
```

Suno will compose melody/chord progressions appropriate to the style.

## Common composition mistakes

- Too many chord changes (overwhelming)
- No chord changes (boring)
- Melody doesn't fit lyrical rhythm
- No bridge or contrast
- Weak ending (just fades out)
- Genre conventions ignored