Play the lydian (iv) scale on the ukulele
Lydian mode is the fourth mode of the major scale. With its augmented fourth, it's even brighter and dreamier than the classic major mode.
Intervals table
| I | II | III | IV | V | VI | VII |
|---|---|---|---|---|---|---|
| Root | Major second | Major third | Augmented fourth | Perfect fifth | Major sixth | Major seventh |
| 0 | 2 | 4 | 6 | 7 | 9 | 11 |
| — | +2 | +2 | +2 | +1 | +2 | +2 |
Theoretical construction
Lydian mode is the fourth degree of the major scale. If you play a C major scale starting from F, you get F Lydian. Its unique characteristic is the augmented fourth (#4), a tritone above the tonic. Its tonic chord is Imaj7 or Imaj7#11. Lydian mode avoids the fourth-third dissonance of major mode (the perfect fourth creating friction with the major third) by using #4 which harmonizes perfectly. It's the preferred mode for Imaj7 vamps in jazz and 'out' solos in fusion.
Position examples
Example with A Lydian (IV)