A Major 7th ♭5 Chord
A Major 7th ♭5 is built from the notes A, C♯, D♯, G♯. The interval from A to C♯ is a major 3rd (4 semitones), from A to D♯ is a tritone (6 semitones), from A to G♯ is a major 7th (11 semitones). This chord contains 3 sharped notes.
The minor-major 7 flat 5 combines a diminished triad with a major 7th. It's a rare, mysterious chord with an almost otherworldly tension — you'll mostly hear it in jazz and film music where composers want something unsettling.
Built as R, ♭3, ♭5, 7, this chord layers a major 7th over a diminished triad. The combination of the dark diminished foundation with the bright major 7th creates a unique push-pull quality. It can function as an altered passing chord or a chromatic approach chord.
Rarely encountered in standard repertoire, so there are no "standard" shapes. Build it by taking a m(maj7) voicing and flatting the 5th, or take a dim chord and add the major 7th. Usually played as a 4-note voicing on the inner strings.