[Feature Idea] Add the ability to playback chords/scales

[Sintrastes]

It would be helpful (especially for very unfamiliar scales/chords) if the app were able to play back the current chord/scale that is currently being looked at.

This could either be on a per-note basis (the user clicks on the relevant note in the fretboard and hears the corresponding note of the scale), or a dedicated button to run through the whole scale/chord, or even to play the whole chord at once.