Lydian mode

The modern Lydian musical scale is a rising pattern of pitches comprising three whole tones, a semitone, two more whole tones, and a final semitone. This sequence of pitches roughly describes the fifth of the eight Gregorian (church) modes, known as Mode V or the authentic mode on F, theoretically using B♮ but in practice more commonly featuring B♭ (Powers 2001). Because of the importance of the major scale in modern music, the Lydian mode is often described (or learned) as the scale that begins on the fourth scale degree of the major scale, or alternatively, as the major scale with the fourth scale degree raised half a step.

The name Lydian refers to the ancient kingdom of Lydia in Anatolia. In Greek music theory, there was a Lydian scale or "octave species" extending from parhypate hypaton to trite diezeugmenon, equivalent in the diatonic genus to the medieval and modern Ionian mode, i.e., the modern major scale: C D E F | G A B C (Barbera 1984, 233, 240). In the chromatic and enharmonic genera, the Lydian scale was equivalent to C D♭ E F G♭ A B C, and C C E F F A B C, respectively (Barker 1984–89, 2:15), where "" signifies raising the pitch by approximately a quarter tone.

...
Wikipedia