Lonesome Fiddle Blues
I love this song. It's a great study on the key of Dm, and I've included some scales and an arpeggio pattern for you to shed at the end.
Also, this B section is great! Usually, it's just improvised, but I wanted to give you something a little challenging to work on :).
The E7 to A7 transition is particularly cool and highlights some very cool transition scales and melodies.