The bass in Francis' hands wasn't a 4-string or a 5-string bass guitar, nor was it a 6-string model. No, readers, this yellow-finished low-end behemoth was a (by our count, at least) 17-string bass.

Last Saturday (Nov. 5), when ZZ Top played the Mark C. Smith Concert Hall at the Von Braun Center in Huntsville, Alabama, Francis momentarily swapped his regular bass for the bright yellow 17 ...