Plugin comparison
Specs, price and the Dubspot Score, side by side — with our verdict on which midi tool to buy.
Independent score / workflow fit / buying signal
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Contenders
Scaler 3 is a chord and music-theory MIDI assistant from Scaler Music. Score 8.6/10, price $99, formats and comparisons.
Melody Rack is Song Cage's MIDI effect: sing or play a melody, then fourteen harmony-aware slots write chords and parts. $59, or $39 for Song Cage owners.
Technical matrix
| Signal | Scaler 3 | Song Cage Melody Rack |
|---|---|---|
| Price | $99 | $59 / $39 owners |
| Dubspot Score | 8.6 | — |
| Formats | VST3, AU, AAX | AU, VST3 |
| Product type | chord and music-theory MIDI assistant | — |
| Developer | Scaler Music | — |
| Typical price | $99 | — |
| Formats | VST3, AU, AAX | AU + VST3 macOS 11+; VST3 Windows 10+ |
| Primary job | progressions and scale-aware writing | — |
| Catalog status | Current as of 2026 | — |
| Type | — | Harmony-aware MIDI effect |
| Effects | — | 14 slots including Chords, In Key, Harmony, Bones, Reply, Morph, Arp |
| Trial | — | 14 days, free Song Cage account |
| Price | — | $59, or $39 for Song Cage owners |
See the full plugin database for more comparisons.