11th

Chords can continue to be expanded past the 9th to 11ths and 13ths.


Elevenths:

A plain 11 would indicate a dom 9th chord with the note an 11th above the root (octave plus a perfect 4th) added on.

Obviously there are a lot of ntoes to play with one hand.
Chord can sound very muddy when played in closed spacing.

Such is chord is more easily handled if it is renamed.

Take the top 3 or 4 notes as a chord and indicate the root using slash chord notation.

C11 or C11 b9 -- frequently seen as Bb/C or a Gm7/C
or Bbm/C or Bbm6/C

These modern voicings of 11th chords (without triad and sometimes with no 5th) have become very common in the contermporary pop vocab.

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There is one 11th chord that is more likely to be called an 11th (rather than a slash chord). It is the sharp 11.

Here the added note lies an aug 11th (octave plus aug 4th) above the root.
The #11 is usually added onto a dom chord but once in a while, it also shows up in maj 7th chords.