A sixth chord is a chord where a sixth interval is added to a basic major or minor triad, creating a warm, and sometimes slightly nostalgic sound. The sixth in these chords typically adds harmonic richness without the tension of more complex extensions like sevenths or ninths.

Sixth chords have a softer, more colorful sound than a basic major or minor chord. The added sixth note gives a hint of jazz and blues flavor. Sixth chords are common in jazz, blues, soul, and pop music. They’re often used as alternatives to major or minor chords to add warmth and complexity without creating dissonance.

Sixth chords are a great way to enrich your chord progressions on guitar and give them a unique character, especially when used as substitutes for plain major or minor chords.

There are several sixth chord shapes that are portable and can be played anywhere on the neck.  

Portable Sixth chord with the root note on the 4^th string

Portable Sixth chord with the root note on the 5^th string