Both are definitely about dancing. Uniting them is an emphasis on interlocking rhythms. Beyond speed and dexterity, listen for memorable melodies, warmth and personality. The Blues Raw emotional power sets a great blues artist apart from the average. Whether it's heard in the acoustic Delta setting, with electric instruments, or vocally, listen for real life stories and the spirit with which they are delivered.
Technical virtuosity helps, but more important is true grit.
Some favor contemplative hymns. Others go for foot-stomping gusto. Listen for purity of voice and dynamic presence. If you feel a shot of redemption, it's good gospel. Today, most traditional bands trade solos in the middle of songs.