The diminished 7th chord is the most villainous chord of them all. If you want to create some tension and suspense in your playing then this is the one for you!
A diminished chord is really easy to play. All you need to do is create a stack of minor 3rds. So to play a diminished 7th beginning on D you would play D-F-Ab-Cb (aka B) and you’ve got it! You can use this formula of stacked 3rds beginning on any key. if you began on A you would play A-C-Eb-Gb. On F you would play F-Ab-B-D. Try this in as many keys as you can. Not only will it help you to learn all the diminished chords, but it will also help you to really understand how a minor 3rd is built and how it sounds.
To make a progression using this villainous chord that sounds really suspenseful, try playing it chromatically. Pick a starting point and then create a diminished 7th moving up in half steps. If you play it broken or arpeggiated it will sound even more fun!
Have a villainous time practicing this chord.