No one knows what this thin length of wire is made of, only that it is so light as to be weightless, virtually indestructible, and almost completely invisible to all known senses.  It is so difficult to perceive, in fact, that even its wielders themselves are often not entirely sure that it exists.  Among those that believe in its existence, many have even argued that the effects it produces can be written off as nothing more than skill on the part of the wielder, placebo, or even pure happenstance.  The greatest myths even suggest that a man used it to charm God Himself, but who could believe such a thing?

 As a part of the process of Attuning to the item the user integrates the Chord with their chosen string-based musical instrument, attaching it in such a way that it can be used in conjunction with, or in place of, any of the other strings on the instrument.  A person familiar with the instrument can attempt a DC 35 Investigation check while inspecting it to notice the Chord.

This item begins with 1d10 charges, with a maximum of 10 charges.  The Chord regains 1d[max charges] charges at the end of each long rest.  The maximum number of charges increases by 1d10, with a limit of 100 total charges, each time the wielder surpasses themselves by advancing their musical abilities to new heights.  When the cap is increased in this way the Chord regains a number of charges equal to the increase in the maximum capacity.  These charges, and capacity, reset whenever a new user attunes to the Chord.

While the Chord is attached instrument, it causes the instrument to become an "Instrument of the Bards" if it is not already.  In addition to the normal Instrument of the Bards spells, it gains the following signature spells at the listed maximum charge capacity tiers:

15 - Tasha's Hideous Laughter

30 - Otto's Irresistible Dance

50 - Holy Aura

Whenever the user spends at least 1 minute playing music with the instrument containing the Chord that is heard by a "noble" being they can utilize the chord and expend a number of charges to produce an effect listed below. A DC 20 Insight or Arcana check is needed to determine that these effects are not natural, DC 30 to associate them with you.

1-4 charges - Gain a +[charges spent] to the next [Charisma]-based skill check made to interact with all nobles that heard the sound as they experience a slight positive mood swing.

5 charges - Gain advantage on the next [Charisma]-based skill check made to interact with all nobles that heard the sound as they feel a surge of source less pleasure. 

6-9 charges - Same as the combination of 5 + 1-4, depending on the number of charges spent, and the targets are Charmed.

10 charges - You may cast the Suggestion spell on all affected targets once without expending a spell slot nor providing verbal or material components.  Alternatively, the target noble[s] must make a wisdom saving throw or be Incapacitated with joy for 1 minute.

50 charges - You may cast the Dominate Monster spell on all affected targets once without expending a spell slot nor providing verbal or somatic components.

100 charges - You can cast with Wish spell once without providing a verbal component nor incurring stress for using it for an effect other than duplicating another spell.  Alternatively, you may replicate the effects of the Cleric Class Feature Divine Intervention as though you were level 20.

Notes: Bard