251 Share definition Flag The fundemental jazz chord progression. Taken from II-V-I, or more descriptively, IIm7-V7-IM7 An example of a 251 progression in the key of C major is: Dmin7 (2 or II is 2nd scale degree of C) G7 (G is 5 or V scale degree of C) Cmaj7 251 by kwajazz July 24, 2006 0 0 Get merch Get the 251 mug. Buy Now — $32.95 See more merch