cord, chord, accord

Cord or cord means a thin rope, or the wire of an electrical device--
The cord won't reach the outlet. We'll need an extension cord.
Have you seen the cord for the radio?
Get some cord at the hardware store to use for a clothesline.

Chord or chord ( rhymes with cord ) means a set of musical notes played together--
He is upstairs practicing a new guitar chord.
She'll have to be a little bigger to play a chord.
"The Lost Chord" is a favorite from the 19th century.

Now that you know that, you can say--
"You can use the headphones and cord from your CD player so we won't hear you practicing that chord on the keyboard."

Note--"accord" ( one word ) means an agreement of some kind, verbal or in writing--
It took them all week to reach an accord on global warming.
Not to be confused with "a cord" ( two words ), meaning a thin rope or wire for an electrical device--
Do you need a cord for your laptop?
Note # 2--an "accordion" is a musical instrument commonly called a "squeezebox"--
The old people liven up when they hear a polka played on the accordion.