Musical Theory Behind Ska

Musically, Ska is a fusion of Jamaican mento rhythm with R&B, with the drum coming in on the 2nd and 4th beats, and the guitar emphasizing the up of the 2nd, 3rd, and 4th beats. The drum therefore is carrying the blues and swing beats of the American music, and the guitar expressing the mento sound. 

`[SB(JJ)]' 

Brendan Tween mentions that the Skatalites frequently used a G-Em-C-D guitar progression, while most modern ska uses a straight 1-4-5 progression (A-D-E C-F-G), although A-D-E9-A is another possible progression. 

Ska features a strong bass and drum rhythm section, guitars, keyboards and brass.