B flat Major sharp fourth

The symbol maj♯4 (sometimes encountered as a shorthand for Lydian-type major harmony) highlights a raised fourth degree against a major triad or major-seventh frame. Depending on chart style, it may imply a major chord with ♯11 color, a Lydian mode emphasis, or a voicing choice that stresses ♯4/♯11 without spelling every extension explicitly. Treat the exact spelling as context-dependent: the bass line and surrounding chords determine whether listeners hear it as an add♯11 color, a maj7(♯11) stack, or a modal tonic on IV in major.

Construction

Conceptual core: major third plus a raised fourth/♯11 color above the bass. In Cmaj♯4 thinking, ♯4 is F♯ against C.

Usage

Film scoring for “floating” major brightness, jazz voicings with Lydian color, and modern pop production on I or IV chords.

Examples

• IV Lydian loops in contemporary production
• Jazz charts that mark maj(♯11) on tonic or IV
• Keyboard pads that emphasize ♯11 over a major bass

Play

Keep the major third clear, place ♯11 high enough to avoid muddiness, and resolve it by step when you want a classical sense of direction.