Db Ionian

The Db Ionian mode (also written C#) — Db Eb F Gb Ab Bb C — shown across the guitar neck.

Also written C# Ionian. C# and Db are the same pitch — Db is the spelling in common use.

Swipe the neck sideways to see the higher frets.

Db Ionian is the major scale — same seven notes, same order. The mode name describes which chord you treat as home, not a different set of notes.

The tool shows this from its parent key, Db major, with Db marked as where Ionian begins, the same seven notes centered on Db.