JEFFEHOBBS  Perfectly realized, elegant software. This belongs in the toolbox of every musician and music teacher.  
(Version 2.0)

LUMPY  Agree with other reviews here, this is a great widget especially for someone like me who is a self-taught, mostly play-by-ear guitar player and part-time keyboard player/noodler

It would be outstanding if this could have direct integration with Garageband, where the selected chord could be automatically written to a software instrument in Garageband at the playhead position.  
(Version 1.0)

INTERSTITIAL  This is freakin' cool. Thanks.  
(Version 1.0)

JEFFEHOBBS  What a fantastic widget! And beautifully done, too. The only feature I could think to add would be the ability to hear the chord.  
(Version 1.0)