Which scale is described as a major scale with a raised 4th degree?

The Lydian scale is indeed characterized as a major scale with a raised fourth degree. In the Lydian mode, the structure of the scale creates a unique sound that is often described as bright and ethereal, due to that augmented fourth interval when compared to the standard major scale.

To provide some context, the major scale itself follows a specific pattern of whole and half steps, while the Lydian scale alters this pattern slightly by increasing the fourth note by a half step. For example, in C Lydian, the notes would be C, D, E, F#, G, A, B, compared to the C major scale, which contains F as the fourth note. This alteration is what gives the Lydian scale its distinct quality.

Understanding the characteristics of the Lydian scale can help in recognizing its applications in various musical contexts, such as film scoring or jazz improvisation, where its unique sound is often sought after.