Chord Transposer is a JavaScript application that I created in response to a challenge. Chords are input, separated by commas. The Key input is necessary for determining if the output key has sharps or flats. The new key and chord progression is output at the bottom of the page.

This app can handle complicated jazz chords as well as slash chords and can transpose either upward or downward in half-step increments.

Just for fun, there is a random background color generator button. With each click, a new background color will appear.