C# Major Seventh chord (C#maj7) on the guitar fretboard

The C# Major Seventh chord (C#maj7) is made of C# (the root), E# (major third), G# (perfect fifth) and B# (major seventh). The fretboard shows every one of them across the neck in standard tuning (E A D G B E), and plays them back so you can hear the chord.

The major seventh stacks a major seventh on top of the major triad, so the top note sits a semitone below the next root. The map shows four notes, each repeating across the neck, and the root and seventh are close neighbours wherever they land. Lower that top note and you get the dominant seventh.