Change duration of notes inside a variable

[Caio Barros]

Hello, is it possible to set a variable with just the pitches of a chord, for instance, and change its duration latter?

I'm thinking in something like this:

%%%%%%%%%

myChord = <c e g>

\new Voice {
\relative c'' { \myChord4 \myChord2 }
}

%%%%%%%%%

or maybe, if it is possible, the durations of many pitches inside the variable.