Guitar chords in the key of C# major

The seven chords of C# major are C#, D#m, E#m, F#, G#, A#m, B#dim. Each one has a job in the key, and each tends towards particular chords next.

• C#, the tonic of C# major. Usually goes to F# or G#: the first move away from home, and the one that does not raise the stakes.
• D#m, the supertonic of C# major. Usually goes to G#: roots falling a fifth, the strongest root motion the key has.
• E#m, the mediant of C# major. Usually goes to A#m: roots falling a fifth, and vi is where iii most often lands. It contains the key's leading tone, so it leans towards the tonic.
• F#, the subdominant of C# major. Usually goes to G#: subdominant into dominant: the standard approach to a cadence.
• G#, the dominant of C# major. Usually goes to C#: the tritone resolves: the leading tone rises, the seventh falls, and the phrase is over. It contains the key's leading tone, so it leans towards the tonic.
• A#m, the submediant of C# major. Usually goes to D#m or G#: roots falling a fifth, straight into the standard approach to V.
• B#dim, the leading-tone chord of C# major. Usually goes to C#: it is V7 without its root, so it wants the tonic just as badly. The ♭5 puts a tritone inside the chord itself, so it cannot be sat on: it is heard as tension wherever it stands, and it is used on the way to something rather than as a place to arrive. It holds B♯ and F♯, the tritone out of V7, so it carries the dominant's tension wherever it sits. It contains the key's leading tone, so it leans towards the tonic.

Where a chord tends to go follows Walter Piston’s table of usual root progressions in Harmony (W. W. Norton); see the sources.